DSB, Corals and Fish - 06/27/05
Hello! (again)
<<Howdy!>>
I had emailed you earlier and had gotten a speedy response to my questions--thank you very much!  But, I am back again with more questions.  I do not have a tank yet, but it will be a 29 gallon tank with a DSB (5") and live rock.  The inhabitants will be some of the following, I haven't made a final decision yet--I know all of them will not fit in the tank--can you advise me which would be best inhabitants for my tank?
<<Will give you my opinions, yes <G>.>>
-pair of clownfish percula, false percula, or Clarkii
<<In a 29 gal. these will likely become the "bullies" of the tank.  Many folks don't realize just how aggressive (and mean) clownfish can be.>>
-pajama cardinal
-mandarin fish--my favorite! he will be added at least six months later after my reef is ready
<<Mandarins are NOT recommended at any point in time with this size tank...just not big enough to support a large enough colony of micro-crustaceans to feed/keep it alive.  The mandarin will slowly starve to death.>>
-long nosed hawkfish--I am concerned that he will eat the shrimp.
<<Yes, a possibility.>>
-jawfish--another favorite
-Banggai cardinal
<<About the neatest "black and white" fish you'll find.  A bit more aggressive than the pajama cardinal, and as such maybe a better choice to house with the clowns.>>
-pair of scarlet cleaner shrimp
<<Beautiful crustaceans.>>
-blue-legged hermits
<<Hmm...if you must...>>
-blue Linckia starfish---six months later
<<Do look to the hardier Fromia species...Linckia starfish never seem to fare well/long in captive systems.>>
-and a fish/invertebrate that will stir up my DSB
<<With a sugar-fine sand bed this isn't really necessary...or even desired.  Bio-turbators such as the worms and micro-crustaceans that will naturally inhabit the sand bed will "stir" it enough.  Spend the money on ensuring adequate water movement (for betterment of ALL life in the tank) instead.>>
I believe that the jawfish will not stir the DSB and from research that I need to stir the DSB in order to have a healthy bed--is this true?
<<The jawfish will likely find a spot to its liking and dig/stay there.  In my experience you do not need to stir the sand bed.  Use a fine substrate that won't allow detritus to settle in and provide lots of water flow and all will be good.>>
I am worried that those fish/invertebrate such as sand-sifting gobies and starfish will eat the beneficial organisms and those organisms are my only source of filtration!
<<Not filtration so much, but VERY beneficial nonetheless.  And yes, gobies and especially a sand-sifting star, can decimate the fauna in a sand bed in a hurry.>>
Is there an animal that will stir up the sand without eating my filter? --If such an organism is necessary.
<<Not necessary re my earlier comments.>>
I also am interested in adding soft corals such as: pulsing Xenia, Tubastrea, frogspawn, anthelia, and an anemone or hammer coral for my clowns--I think the Hammer coral might be a better choice because it will not eat my mandarin fish, but I like the look of an anemone.
<<Anemones really do require specialized/specie specific tanks and expert care.  Please do restrain yourself from purchasing one.>>
I think  that the Tubastrea may not be happy in my tank because it lacks the ability to produce zooxanthellae and prefers weaker lights in comparison to other corals.
<<Another coral requiring specialized care.  Most starve to death from inadequate feeding.>>
I am more confident that the other corals will be happy in my tank as long as they don't overcrowd and fight with each other for territory.
<<They WILL fight...tis a fact of nature.  But as you already are aware, not overcrowding, along with proper filtration (skimming) and frequent partial water changes can mitigate the dangers.>>
Will two 55 watt PC be enough for those corals?
<<For what you have listed (excluding an anemone), yes, I would say so.>>
The dimensions of the tank will be 30" long, 12" wide, and 18" deep.  I read in a book that this is the minimum requirement, and with my small budget I am hoping this will be suitable for those corals.
<<Lighting is only part of the equation...proper feeding and water flow are just as important to coral health/color/survival.  Don't get too hung up on the lighting.>>
But, if they need more light I will gladly purchase it for them. Of course, the corals won't be added to my tank for at least four months, and I will add them one at a time.
<<Very good.>>
Do you advise installing PC when I first get my tank, even though there won't be corals right away?  There will be live rock and fish- This is expensive, but changing from NO to PC may be more expensive then initially using PC. My concern is that the fish may not like such high wattage and that there will be more algae blooms.
<<The fish won't mind the light at all...and algae will be controlled by not stocking the tank too fast, along with diligent husbandry/frequent water changes.  But most importantly, be sure to cycle the tank properly through the natural algae succession before adding ANY livestock.>>
One last question...When I put the 10 pounds of live sand that Bob recommended for my tank, should I place it on the bottom layer of sand and the rest of the sand on top of it? Or should the LS go on top and the regular sand on the bottom?
<<I would place the "live sand" on top.>>
I also think that perhaps a mixture of crushed coral and "sugar sand" will not be as beneficial for filtration as a DSB of only sugar sand would be.
<<Agreed>>
But, won't the jawfish need substrate of different sizes?
<<You can add a small amount (handful or two) of crushed coral/broken shells for the fishes benefit.>>
Thank you very much for your time! I appreciate all your help as I am trying to learn from mistakes before I make them. Thank you very much again!
<<Thank you for taking the initiative to ask BEFORE getting in to trouble.  Do have a search/read through our archives...much more "learning" to be had than what I can share here.>>
Jennifer
<<Eric R.>>

Cyanobacteria and DSB
Hi, I have a question about Cyanobacteria in my tank (120gal, ~5" Southdown play sand DSB, ~70lbs or rock, close loop circulation Anthony's design powered by Dolphin AquaSea pump ~2,100 gal/hour, built-in glass overflow Anthony's design with a sump and Iwaki 20RLT pump, 2x 250W MH Ushio 10,000K + 2x 65W Actinic PC, TurboFlotor 1000 skimmer, home made CO2 calcium reactor using Knop Korallith).  Currently I have what I believe a very low bio-load in the tank (one juvenile Six Line Wrasse, one juvenile Banggai Cardinal, Cleaner Shrimp, Cerith snails (a lot), a few blue legged hermit crabs, ~10 SPS frags and some softies).  I should also mention that I use RO/DI water (membrane, sediment filters and GAC replaced around X-mass) for water changes 5gal/week (it sits for a few days in a bucket with a powerhead and then I add the salt and after it sits for another day or so then I use it for water changes)
<All good thus far...>
and that I do check the specific gravity, temperature and pH before I use it.  I run activated carbon 24x7 and I've been always using Black Diamond. In the recent month it was somewhat difficult to obtain and so I've used other brands as well (Pro-Carb & Kent Reef Carbon).  I have been changing about a half of the carbon every other week and cleaning the sump about once a month.
Over past two month I've been observing small patches of Cyano spreading over the sand bed.
<Happens>
My lights (bulbs are less than 6 month old) go on at 12:30pm and go off at 11:30pm in the evening.  Early in the morning I can't almost see any Cyano but as the day goes on it is more and more visible.
<Well stated>
When the lights are turned on the Cyano starts slowly disappearing with the exception of the places that are brightly illuminated.  By the time the lights go off a lot of it disappears.  I've started being VERY careful about how much I feed the fish (once a day with a turkey baster trying to feed as fast as they can catch the food to minimize any food being uneaten).  I'm feeding a home made frozen food containing some Nori, scallops, shrimp, krill, brine shrimp and Selcon.
Since the Cyano appeared I started executing water changes more frequently (about 5 gallons 3 times per week) and cleaning the skimmer collection cup 2 times a week.  While checking all the equipment trying to identify the culprit I noticed that the hose that feeds the skimmer with the raw water was partially blocked by the calcium deposits that accumulated on its walls and subsequently got loose.  I guess this can explain why the water quality deteriorated and DOC concentration increased.
<... would think it would decrease>
I have noticed that about a month ago, cleaned up the skimmer and the hoses immediately and have been checking it once a week since.  I had also some issues with the calcium reactor and the pump re-circulating the water within the reactor.  This lead so drop in the alkalinity and Ca levels, which I have tried to correct for a short period of time with dosing both Seachem's Reef Advantage Calcium (calcium oxide) and Kalk shots (as advocated by Anthony in his book).  Once I got the necessary equipment, I fixed the Ca reactor and phased out any other dosing.  Now the alkalinity is around 3.77 meq/L (Salifert), Ca 360ppm (Seachem), Total NO3 Nitrate ion concentration is below 12.5mg/L (Tetra), Phosphate is not detectable (Seachem) and the pH is between 8.1 (morning) and 8.2 (evening) (Seachem).
<Again, all sounds good>
I tried to vacuum some of the Cyano from the surface of the sand bed with as little of the sand as possible and noticed that about ¼ inch thick top layer of the sand is bound (not fused) together.  It can be broken up easily with the hose I used to vacuum the Cyano or with the scraper.  
I acknowledge that my water quality has not always been perfect (I used to have a yellow tang and used to feed more heavily) but I think that it has improved a lot in the last two month.  However, it seems that my effort is not stopping the slow progress of the Cyano.  I have been reading various articles on the net about DSB lately and notice a few that talk about so called "crash" of DSBs and how Cyano problem is indicative of such crash.  Is my DSB crashing?
<Doubtful, no>
  Can I recover from this problem or is the DSB doomed to be completely replaced?
I will be looking forward to your reply.
Regards,
Petr
<Mmm, well, you really don't have a "problem" as far as I can see, evaluate from the above... transient Cyano/BGA is common... to nearly unavoidable, given the make-up, maintenance you list... There are a few things you can do to speed up the "centering" of the system (that will occur in time...). You might convert part or all of the sump to a lighted refugium, with purposeful macroalgae... You could upgrade your skimmer... You might add an ozonizer... Or "just relax" and not sweat this small, likely transient occurrence. Bob Fenner>

One Or Two DSBs? - 08/20/05
G'day Crew...
<<Howdy!>>
Halfway through the design phase for a marine biotope, due to the insistence of SWMBO I asked a home builder friend of mine to check out the load-bearing capacity of my house (slab on grade) and sure enough, the footings built to code here in southeast Georgia (American, not Asian) won't be able to support the massive installation of my dreams.  Sigh...
<<Interesting...  I have a home built on brick pillars (no slab) in South Carolina...and a 500 gallon reef system in the living room.  Now, there may be dynamics involved with a slab I'm not aware of, and I mean no disrespect to your builder friend, but a hundred dollars or so invested in a "structural engineer's" time might prove you CAN have that massive installation.>>
In the interests of domestic tranquility, and structural integrity, I am now drafting plans centered around a 65 gallon display tank with a 29 gallon refugium hidden in the stand.  Aqua-C Remora skimmer and Chaetomorpha for filtration and nutrient export, plus a happy habitat (Honeymoon Suite) for 'pod
reproduction in the 'fuge.
<<All good>>
Lighting in the refugium will be alternate with the display tank to help minimize pH swings (if I understand what I am reading in the WWM FAQs).
<<You do>>
Received my copy of "Reef Invertebrates" five days ago and the binding is already showing signs of wearing out <G>.
<<Great book, ain't it.>>
Read it cover-to-cover twice, and it falls open to page 30 when I pick it up.  Which leads (finally) to my question...  If I have a DSB in the refugium, do I need one in the display tank as well?
<<More/bigger is always better, but "no", you don't have to have a DSB in both.>>
I am still not sure what the population of the display tank will be, other than live rock and just a couple of fish for accent.
<<Sounds good now...but will you be able to hold to this stocking plan? <G> >>
During a 'eureka' moment I realized the visual impact of a DSB in the display tank can be masked by using 6 inch baseboard
molding around the bottom to hide the BG algae, diatoms, etc so it isn't really aesthetics driving the design, just wondering what the state-of-the-hobby thinking is along these lines.
<<Subjective really...  I use/like a DSB in both my display and my 'fuge...but I also know successful reefers who don't.  If you plan to keep any burrowing/sand-sifting fishes or crustaceans, you'll want to consider this as well.>>
Or, turning the question around, postulating ZERO bioload, what amount of DSB is needed to support a volume of ~95 gallons holding about 100 lbs of live rock?  What I am wondering is whether there is a 'K' factor about the carrying capacity of a LR/DSB setup where you can calculate that 'X' pounds of LR and 'Y' sq ft of a 5 inch thick DSB will support 'Z' grams of creatures?  My assumption is there will probably be <several> grams of critters in every sq ft of a DSB because...that's what a DSB is, after all.  I've Google till my fingertips bled and can't find anything remotely applicable to this question so I'm appealing to the WWM 'spurts <G>.
<<Likely you won't find such a formula...and no need to make this so complex.  Ideally, you want as many square feet of 5" deep sugar-fine sand bed as you can muster within your physical limitations, and in keeping with your (or your spouses <G>) sense of aesthetics.>>
Thanks for all you do, I truly believe the WWM is the finest resource available to us ignorant, struggling marine aquarists.
John
<<It's not ignorant to ask questions my friend, and your query indicates you're far from same...  Regards, EricR>>

DSB And Pump Returns - 08/17/05
WWM (EricR),
<<Hiya Todd!>>
Thanks again for the great response and all of the previous suggestions are in the workings as we speak.
<<Hope they prove helpful.>>
I have a few more questions before I switch my LR and some tank mates over to the new tank.
<<Alrighty>>
First off is more of a should I do this question.  I am going to put a DSB instead of my old crushed coral base.
<<Yea! (sugar-fine, right?)>>
I want 4-5 inches but I am not sure what kind (I would love the cheap stuff from Home Depot, but its not Southdown and I don't trust the play sand at my Home Depot), so I was thinking of the Coral Sea (0.5-1.5mm).  The LFS store here suggested some
crushed coral but I don’t really trust them yet especially after that comment!
<<A "small" amount mixed in wouldn't necessarily hurt anything, but also affords no benefit so...>>
Do you think that should do fine and not too messy when I move the rocks around or add water?
<<My preference for a DSB is sugar-fine aragonite sand.  Sand from other sources is workable, but doesn't provide the buffering capacity of the aragonite.  I'm not familiar with the Coral Sea product but will assume it is of a marine/calcareous origin and will likely serve you just fine.>>
Also, should I put the same sand in my refugium?
<<I would>>
Last but not least is a question regarding my return lines out of the sump.
<<ok>>
For now I am going to be using a underwater pump (Rio 20, cause that is what I have for now).  I want outflows in all four corners coming from my sump, if you think this is a good idea?
<<Looking at your diagram, yes.>>
If so, then do I have one line up from the pump, place a 'T' at the top of the tank and put one 90 at each
corner...If you look at the tank from the top, it would look like an upside down 'Y'.  There also would be a 'T' at both corners that would have an outlet then another 90 at both ends for an outlet.  I will send a quick schematic to make it easier for you to understand.
<<it did>>
The other option would be to have two pumps in the sump.   One for each side of the tank (two outlets per pump)?"
<<This second option would be my choice...a bit more flexibility/gives some measure of redundancy in case one pump fails.>>
Also, would a 1" PVC pipe do the job (from the pump to the outlet in the tank)?
<<Considering the small size of the pump(s), I would use 3/4" pipe with 1/2" nozzles to increase water velocity (figure 300-350 gph per 1/2" nozzle).>>
Thanks again and keep up the good work.
Todd
<<Always welcome, EricR>>

Live Sand Bed 7/4/03
Hello at WetWeb,
<Cheers>
Just reading the live sand bed section in Anthony and Bob's new book, and I have a couple questions.  Let me preface them by saying I recently had to remove the aragonite bed from my 180-gallon reef due to what I believe was phosphate precipitation.
<Yes... does occur... but usually is not a problem unless the bed is stirred or agitated. Else it is neutrally bound>
The bed was like concrete and I was having algae problems, so I opted to remove it.  
<Hmmm... that actually sounds like a water chemistry problem. Adding calcium/Kalk too quick or too much and/or spiking the pH is what causes that. Subsequently, the compromised sand bed can feed nuisance algae or at least not deter it. Point being... the problem was not your sand bed... but the advice you got on how to maintain it>
Removal of the substrate and large water changes seem to have greatly assisted in alleviating the nuisance algae.  I suspect the problem arose from playing the see saw game with alkalinity/calcium, etc., and using additives to try to balance it and instead made it worse.  
<Exactly, my friend>
Out with the old.  I now want to add a new live sand bed and am considering using the Carib Sea Seaflor Special Grade Reef Sand for starters, which is what I had in the original bed that I removed after it became so compact.  There is no specific grain size indicated on the bag of the Carib Sea, so I can't give you that specific information.  If you are familiar with this particular grade, would you opine as to how deep a bed you recommend, and how much live sand and sand stirrers you would add to it to seed the bed?  
<No worries... simply seek sugar-fine grains at a depth of 3" minimum... 4-6" better still.>
I'd like to add a few Holothuria cukes, etc., once its established to keep things clean, and perhaps some critters from IndoPacific SeaFarms to improve the life and stirring of the bed.  This system is old and the buffering capabilities, etc., have greatly reduced, and I would like very much to get it in balance again with a good sand bed.  
<No troubles at all... can be had>
I must admit I'm a bit paranoid after all the work I went through to remove the substrate and alleviate the algae problem.  
<Understood... but easily prevented. Do focus on excellent water flow (10-20X tank volume) and due diligence with dosing supplements (starting with 2-part mixes in a balanced tank, mixing said liquids vigorously before every use (else see-saw occurs), etc)>
Sorry for blathering.  Your suggestions would be greatly appreciated.  BTW, I never give up.  Just want to do it right this time. Many thanks, Peggy
<Excellent to hear! Best regards, Anthony>

DSB & Sump
Hello to whomever is on call at this hour...
<Steven Pro up with the birds.>
My question is this, I am getting ready to deepen my sandbed to around 5" or so, but as I was reading your FAQs, I noticed that there is a mentioning of a DSB in the sump and not necessarily in the main tank, so would it be better to only make a nice deep bed for critters in the sump and not in the main tank?
<I would do both. That is what I am planning on my new tank.>
I have mostly fish with a carpet and a few mushrooms, so a shallow bed isn't ideal for my carpet. Also, how would I get edible critters from the sump to the main tank since the sump is under it?
<Their larvae would reach the main tank by way of the return pump.>
Maybe leave some rock in the sump to accumulate live stuff and rotate rocks out adding edibles to the main tank?
<You could do this, particularly for algae if your main display is over eaten by Tangs.>
Also, I don't have a light on the sump, are there animals that I could leave in the sump DSB, like cucumbers, sifting stars, murex, conchs, or anything not caring if there is light?
<I would just add a few really nice pieces of new rock and see what develops.>
Thanks in advance for your response. Kim
<You are welcome. -Steven Pro>

5" of Southdown Sand
To Anthony Calfo, I put 5 " of Southdown sand in my 180 gal reef tank, just like you said to all at one time . How long will it take to clear the water up .I found the Southdown sand at a Home Depot in Cary NC $4.95 for a 50 lb bag. RGibson
<turbidity depends on how you handle/process the sand. Most people want to rinse away the chalky fine particles but that just makes a miserable mess and prolongs turbidity. The fine particulates are actually desirable and quite soluble. Put the sand dry into the empty tank and fill the tank gently by pumping/pouring the water in to a bucket sitting on the sand bottom. This minimal disturbance will afford an ideal clarity within 24 hours. Else, rinsing or blasting the sand on the refill is sure to cloud the tank for days. Anthony>

Re: 5" of Southdown Sand
To Anthony Calfo:  Should I run the P skimmer while the water is clouded. Southdown was $3.95 for 50 lb RGibson
<certainly... but when the tank is filled slowly in a bucket sitting on the sand, it is quite likely tat no clouding will occur at all. I have set up tens of reef displays where the water was crystal clear from go by this method. Simply avoid blasting the sand with water... a gentle fill will do the trick :) Kindly, Anthony>

Deep Sand Beds
Bryan here, you will be hearing a lot from me as I am researching for my tank setup. I want to learn and research as much as possible so I don't make some of the mistakes I made b/f ( B/F I found your site). Last night I read up on DSB, I want you to clarify a few things and to see if I understand. You need at least 4"-5", (could use a joke here)
<I think I will refrain and let the readers insert their own.>
more towards 5" of a fine reef sand. This depth will harbor anaerobic bacteria beneficial for denitrification and in between depth can be dangerous. Again no coarse substrate so as not to allow detritus accumulation. Very beneficial to have a strong flow/current over the DSB, and no heavy bioload as will defeat the purpose or ability of DSB b/c of accumulation of waste. Now some questions, a DSB w/ LR in a reef set up is all the biological filtration needed right?
<Yes>
Then add a skimmer and mechanical filtration.
<You may not even want or need the mechanical filtration. I prefer to use a sump design that incorporates a settling chamber instead. It allows detritus to accumulate in a small area where it is easily siphoned out.>
I read that you can lightly stir the sand every month or so, and not to vigorous to disturb the bacteria. I also read some people were vacuuming the DSB, which would you prefer?
<Slight disturbance of top 1/4 to 1/2" to get rid of diatoms. If you use the right amount of critters (worms, pods, etc.) you may not need to do this that often.>
How much of the DSB at a time and how deep would you go?
<I do all the visible parts, but no more than 1/2" deep.>
Also what do suggest as far as sand sifters?
<The tiny hitchhiking critters that come with your liverock or livesand.>
Last question, what is the process of replenishing the DSB, say after a few years. Do you want to tank 1/3 of sand out and add new?
<After a few years, your DSB will no longer be as deep due to dissolving. You can lightly add a little at a time to the top. Again, not too much, less than 1/2" at a time so that you do not smother anything.>
Thank you for the advice, Bryan
<You are welcome. -Steven Pro>

DSB
Hi again,
It's regarding DSB. I got sand in my present 4ft tank and intending to add it into the new tank to speed up the process of maturing the tank, however part of the sand is cover with algae.
1) Is your advice to me to add all the sand in my present into the new tank?
<Yes>
2) How to arrange the sands in DSB? 
Bottom - Crushed coral?
Medium - Medium finer sand??
High - Fine sand ?
<I would just use all fine sand.>
I plan on buying some sand sifting sea stars (Astropecten polyacanthus). Is it advisable to have it if I intend to setup a reef tank with little peaceful fish, shrimps and snail.
<No, I do not like to use those starfish.>
3) Is sand sifting sea star reef safe?
<They will not eat corals, but other beneficial life forms.>
4) Will it harm live form or vice versa ?
<They eat many worms and other good creatures.>
Thanks again. Regards, Danny
<You are welcome. -Steven Pro>

Marine Fish only & sandbeds
Hello to Ye of great aquatic knowledge,
<hmmm... so many jokes, so little time>
I've been reading quite a few of your web pages and clicking the various links and I've sent a few emails and had some very informative replies. I'd just like to say thanks before anything else because my tank is looking and doing better than ever. As I gather information to prepare for the next, not too distant aquarium project, I have a few points of confusion I was hoping you would clear up. First, I have a couple of sandbed related questions for what will be a 374 gallon or larger Fish only/live rock setup that I didn't see too much of on the various pages because most people who wrote in seem to be more on the reef end than the large fish end of the aquarium world and the fish people didn't ask my questions for me;
<agreed>
1. I've read the FAQ page http://www.wetwebmedia.com/dsbfaqs.htm (and the other sand bed question pages) and there seems to be common knowledge about deep sand beds in reef tanks and then there are two segments on a page referring to a fish only & live rock tank where Anthony Calfo says "Truth be told, most reef fishes are too much of a burden for our DSB fauna and that is one of the reasons why a fishless, upstream DSB refugium is so popular "
<yep... and this statement does honestly make some assumptions about the typically overfed and or overstocked tanks that are so common. As well, most tanks have no where near enough water flow either. As such, DSB methodologies can be easily corrupted with heavy fish loads (reef or no)>
and Steven Pro says "<I would add the additional LR but not sand. I do not like DSB with FO tanks. The sand bed can too easily become overwhelmed by the influx of nutrients from such greedy eaters as your fish.> which puts both guys on the same page, 
<agreed>
so I would like to ask what would be the opinion at WetWebMedia.com of the ideal substrate (sand, crushed coral ,possibly live rock across the bottom held up 1/4 inch by supports, none, other) 
<bare bottomed is the easiest and ugliest. Anything else is fine if kept shallow enough (1/2 inch or less) so that detritus cannot accumulate easily. Strong water flow is always necessary (no dead spots)
in any tank, and course media is tougher to keep clean>
(mostly) Large Fish only aquarium with a large amount of live rock? From my point of view, sand looks the best and always did, but years ago, the advice I always got was that sand is unhealthy for fish only tanks. 
<that advice was mistaken. Mismanaged sand beds are bad for fishes, properly managed ones are very beneficial if one takes the time to plan and maintain right>
Now, everywhere I go .... fish and sand in the same tank. Healthy combination?
<can be yes>
2. How much substrate (if any)?
<over 5" if nitrate control is needed... less than 1/2 inch if not>
3. I currently use just enough crushed coral to thinly cover the bottom glass in front of the live rock (bare glass under and behind the rock) and use the large ended siphon tube to pull detritus out of the crushed coral during water changes, 
<a fine practice/application>but with a tank as large as I want to upgrade to (minimum 374 gal.), I can't imagine vacuuming that much substrate on a regular basis unless I do a section at each water change and if sand is used is it just as frequent a job? 
<that's what strong water flow (keeping detritus in suspension) and two skimmers are for :) Seriously>
I see many huge tanks in public aquariums with sandbeds on the bottom and I don't get the impression they vacuum the sand .
<massive water flow again><<Most actually do vacuum... but "after hours". RMF>>
What is their routine and if that's not applicable to a home aquarium, 
<easily applicable.. most people just underestimate random turbulent water flow>
what would you advise?
<above>
4. I have read about reef tanks with 2 inch sand beds and then a sheet of plastic screen to keep it undisturbed and then another few inches of sand for critter access, which sounded like a possible plan in a Fish Only/Live Rock Tank before I read Anthony and Stephens comments. 
Am I correct that they are saying the issue is not the sandbed disruption (although that could be a problem with large fish), 
<yes... could be a problem with digging fish especially>
but the fish generated nutrients that would still be a problem even with that much sand on a 120 by 30 inch tank bottom?
<exactly... nutrient overload... such should be in skimmer>
With a screen divider situation, the sand under the screen is to be left untouched always?
<not really the point... needs to be sifted by microfauna... not stagnant>
5. I see these newer products of live dry or damp sand in a bag that allow instant aging and stocking of aquariums. 
<absolutely ridiculous products>
Wouldn't ordinary dry, bagged aquarium sand mixed in buckets with the recommended per tank gallon amounts of saltwater BioZyme or other instant bacteria products have the same basic results? 
<not even necessary... dry sand inoculated in tank with a handful of live... all is "live" in weeks>
Would that be more effective than just adding the bacteria directly to the aquarium? 
<the bacteria products for the aquarium are not much different than adding flake food to rot... they are barely "alive" if at all... simply a usable source of food for inevitable naturally occurring bacteria in tank>
Could home made cement mixture base rock created and cured like the public aquariums do be brought to life (aerobic bacteria anyway)
<no thrilled with this idea>
in buckets with the instant bacteria products? This is part of my master plan (The home made rock) plus the actual live rock I have in the current tank, plus new live rock.
<too heavy... learn fiberglass casting techniques instead... seriously. That's what more big aquariums use>
Sorry to bug you with what is probably basic knowledge to most active aquarists, but although I've had aquariums for 30 years (17 fresh water, 13 salt), I haven't stayed on top of the new methods in the last few years and it's time to catch up! Thanks, Rich
<enjoy the journey, education.. kindly, Anthony>

DSB, NOT Plenum/Jaubert Methodology
Bob,
Thanks for the quick reply. As I've done more research I've now have a couple more questions. The DSB I'm building is for a standard 45 gallon tank, and I was originally going to build off a model system I found in a 1998 copy Aquarium Magazine. For a sixty-five gallon tank it was using one inch of aragonite gravel and two inches of sand over a one inch plenum.
<I want to make a distinction here. When I refer to or even read about a deep sand bed/DSB, I usually think of a static sand bed, no plenum. I use the term Jaubert system to describe sand with a plenum.>
Is this deep enough for a my 45?
<I would refer you to Dr. Jaubert of the Monaco Aquarium and his writings. Many negative things have been said of his system when the tanks in question were not setup to his specifications. I would search out articles by him, if your intension is to build a Jaubert system tank.>
FAQs and information from the site indicates needing a deeper amount. The other question is can I use crushed coral in one layer or all sand? and how much sand would that be? Finally about the "dead space" caused by placing rock on the sand. I plan on using live sand, but I was also going to attempt to minimize the dead space by placing the lowest layer of rock on two inch PVC pipe "cups" above the sand. Will this help?
<Yes, I have seen many interesting ways of elevating the liverock above the sand using PVC, lighting eggcrate, milk crates, and many other food grade plastics.>
Thanks again, Evan J.
<You are welcome. -Steven Pro>

Sand bed
Hello,
<Hi there>
I have recently found your website, and I find myself on here everyday. I find myself totally immersed on your website. 
<Mmm, soon you'll be answering queries!>
I have just purchased my 55 gallon fish tank and a 30 gallon fish tank for my sump. I plan on purchasing a ~20 gallon Rubbermaid container for my refugium. Would it be okay to add a deep sand bed in the refugium (~4in) with live rock and add only 1 in of sand bed for the 55 gallon tank?
<Yes>
And approximately how much water should flow through this refugium?
<A few... 2-3 turns per hour is about ideal)
Thank you for your time.
<You're welcome. Bob Fenner>
Dave

Quick Question about Phosphates and DSBs
Bob,
Besides nitrates, do DSBs or Plenums also remove phosphates? I've articles with conflicting information. Thanks for the help. Evan J.
<Indirectly yes they can. But if phosphates are a concern, you are more likely to precipitate them with Kalkwasser (use gently until the pH reaches 8.6, then they will drop out)>

Final Questions
Bob,
So a "Deep Sand Bed" is basically four to six inches of fine sand (say three inches of "clean" sand and one live on top) put into the bottom of the tank? Only use screens to prevent deep burrowers from damaging the anaerobic parts of the bed?
<Please see here: http://www.wetwebmedia.com/dsbfaqs.htm... yes and often the principal stated reason. Bob Fenner>
Thanks again for all your help.
Evan J.

DSB & "Stuff"
Greetings all,
I just completed the move from New Hampshire to California....it was not an easy task. I am setting up my 48 gallon bow tank and went with a 5 inch deep sand bed (oolitic aragonite)...lord ONLY knows where the fish are going to fit with all that sand. The effective space is reduced to about 15 inches. But the nice thing is that the "bottom" is closer to eye level so viewing critters should be easier on the back. On that subject, I had an interesting experience when fly fishing last month that made me think of the DSB discussions. There had been a fire in the Sierras and the stream I was fishing was full of sediment, about 3-4 feet deep. I stepped in and sank up to my freakin' neck and (after I realized I wasn't going to die in quicksand) I notice the distinct smell of sulfur! It was bubbling up from the bottom of nature's deep sand bed, you could see it rising in bubbles all over the place. It was neat to see a live working model of something we always bandy about here.....so I guess if you go with a 4' DSB you might really have a problem in your tank <grin>.
<I have seen 12" sand beds that did not produce Sulphur gas. At a certain point though, you are not really any more productive as far as denitrification or critters. I aim for 4-6" myself.>
By the way, my wife still insists that the bubbles were coming from my waders.
Anyway...on another note, I noticed that the house I'm in gets up to 86 degrees on REALLY hot days (only a few hot days a year in Silicon Valley
luckily). There's no a/c in the house. Do you think I might need to spend a zillion dollars on a chiller?
<I would much rather spend the money on AC. Even a one room unit is more cost effective and makes watching the tank more enjoyable.>
Also, I'm on the hunt for some decent live rock in the south SF bay area so if anyone knows of a good retailer I'd be grateful for a referral.
<Do ask for recommendations from online message boards. Ours is at http://wetwebfotos.com/talk/index.jsp>
Enough rambling for now. Thanks so much for all of your help. Don't ever quit, I won't know what to do. Wes
<And neither would we with all the free time. -Steven Pro>

DSB Vs Jaubert
Hi, Bob & Experts
Please help, I confused between DSB and Jaubert. Most said that DSB is better the Jaubert Plenum system and only few agreed on Jaubert system. Can please enlighten me on the pros and cons of both system?
<Far too much to say in a short email. I will say I have used and continue to use static DSB's 4-6" deep without problems. I have nothing against the Jaubert system, I have just never needed it.>
Thanks, Danny
<You are welcome. -Steven Pro>

Wrasse vs. DSB
sorry to email you directly...I can't for the life of me figure out how to post a question on wet web media for you.
<when you like, you can go here http://wetwebfotos.com/talk/ and click on a folder/topic of interest. Then once on that folder, click the link near the top of the page that says "post new topic". Simply type in your question and when finished click "post message">
is there any truth that a fairy wrasse would be harmful to a DSB system in any way? i.e.: eating pods or other necessary inhabitants or otherwise causing havoc? 
<definitely not "causing havoc". If so by that measure, then clownfish, damsels, pseudochromids and many other popular fish are far worse. Yes, the fairy wrasses will eat zooplankton: but so will corals and most other fishes, yet we are keeping them from reef tank either <smile>. Truth be told, most reef fishes are too much of a burden for our DSB fauna and that is one of the reasons why a fishless, upstream DSB refugium is so popular (plankton blooms and overflows nightly to feed tank without the main "colony" ever being decimated by fishes>
thank you. dr. drew
<best regards, Anthony Calfo>

Collection and Reefs
Bob:
First. What is the ISBN of your book... I can't seem to find it.
<Please take a look on Amazon.com under title, or my name>
Second. I live in Puerto Rico, and thus have access to unlimited amounts of some of the most beautiful reefs (my opinion) in the Caribbean... I would like to collect some "live" sand myself. My big idea was to go somewhere somewhat deep and with a weighted bucket and a rope (I know, kinda unsophisticated) drag that baby and pull up the results.
<Yes>
Several questions come to mind, and I cannot find anything this specific in the archives...
1. This will actually be the same or even better than packaged stuff right?
I mean, I can go from the reefs to my house in under 30 minutes...
<Maybe... a good idea to at least rinse lightly (in seawater), decant, and store in an aquarium setting for a good two weeks before using >
2. Parasites come to mind. Any way to kill the little suckers before using the sand?
<All sorts. Please read through WetWebMedia.com re Live Sand: http://www.wetwebmedia.com/livesand.htm and the associated FAQs file>
3. If the commercial sand being sold is reef sand, why would the sand in the reef down here have silicates? Do they not come from the same place?
<Yes, about a third or so silicon dioxide based. Don't come from same places specifically (collected, sorted on beaches for the most part)>
4. I also think that I would like to collect some fish... I did get a permit for this from the local Natural Resources dept, that you know of in my area, what are good specimens to catch?
<In Puerto Rico? All sorts of areas... again, please read through the WWM site... "Collection", Quarantine...>
5. What foreseeable dangers do you see in collecting fish by snorkeling in a reef? (sharks, Scorpionfish, jellyfish)
<Other divers, yourself... perhaps Fire Coral, Sea Urchins... really>
Is scuba a must? What kind of fish can I expect to catch this way? Realistically?
<Practice and study makes perfect my friend.... many and enough organisms can be easily gathered by snorkeling. Bob Fenner>
Thanks for your help!
Hugo S.
San Juan, Puerto Rico

Re: Collection and Reefs
Bob:
Tank you for your prompt response, I can't imagine how many e-mails you must read a day!
<Am sure you can... a couple hundred...>
I found the ISBN in Amazon.com... Thanks.
<Very good>
You said that about a third of sand comes from here, maybe I didn't understand quite what you meant.
<Sorry for the lack of clarity. I meant to state that about a third of the sand you're likely to find is silicate-based... only about another third is calcium carbonate-based. Alternatively, the various companies (e.g. CaribSea) try to collect, clean and bag almost 100% carbonate-based materials>
Did you mean that a third of the wrong type of sand comes from the Caribbean/Puerto Rico?
<Actually, about this amount comes from "sandy bottoms" in most places off coastlines... some more than others. You'd be better off looking for a beach area, at accumulations of hard materials and screening/sieving out the small "silica" (shiny, flat, angular) materials in an attempt to collect just the "shell and coral skeleton based" ones. Please read: http://www.wetwebmedia.com/marsubstr.htm and the FAQs beyond>
By Silicon Dioxide did that mean that it has silicates? 
<Yes>
Also, where does aragonite come from usually? Specifically?
<Mined, crushed, sorted, cleaned calcium carbonate material from "ancient" reefs. The coarser material is extracted from a few places in the world, the finer (oolithic) from areas of the ocean where it forms spontaneously, accumulates. Please read: http://www.soils.wisc.edu/virtual_museum/aragonite/>
If I let the sand dry and then sift it for the correct size (sugar sized), then this would kill the whole "live" concept right?
<The "macro" parts, yes. The "micro" (e.g. bacteria, funguses, viruses...) would likely persist to some degree>
Would this reef sand be small enough for a 4" DSB? How much sand would you say in pounds or gallons it would take for a 4" DSB?
<Please read over WetWebMedia.com re Deep Sand Beds. Bob Fenner>
Thanks!
Hugo S

DSB OR Expensive Protein Skimmer
Hello Bob
<Hello Antoine>
I have a 280gal FOWLR Tank 60x30x30 with a 11" Vlamingi Tang, 7" Red Coris Wrasse, 6" Twin Spot Wrasse, 5" Pink Tail Trigger, 16" Snowflake EEL, 12" Golden Tail EEL, and a newly acquired 18" Leopard Moray. Now what I'm in the process of doing is removing the Snowflake and Golden Tail EEL to a 75 gal tank. I think that I will trade my Pink Tail Trigger in at the LFS for a miniatus grouper or Formosa wrasse since he is always being harassed by the Vlamingi tang.
<Okay>
Now since I acquired the Leopard moray I'm putting a strain on my filtration system. Water parameters have moved up Ammonia .1ppm, Nitrite.2ppm and Nitrate up to 60ppm.
<Yikes... I would forestall feeding till there was/is no ammonia or nitrite period>
Everything was at zero except for the Nitrate being around 35ppm. I'm thinking that this is probably going on because of the undersized skimmer. I ordered and now have in possession another Turboflotor 1000 that I was going to use on my new 75 gal but now I'm wondering if I should send it back and get a Euro-Reef CS8-2 (requires less adjustment correct) for the 280 gal or just add a 20 gal sump DSB with about 6 inches of fine sand which would be a cheaper way to control my water parameters and use the turbo-flotor on the 75 gal. 
<I would get the bigger, better skimmer for your larger system for sure>
My goal is control denitrification and have to do less maintenance. I thought about a refugium but this would require me to cut the Caulerpa back all the time and worry about it dying on me causing a possible disaster.
<Not a huge concern>
The original Turboflotor did great until I added the leopard moray and I know as he grows that he will put a greater strain on my system. I just don't know if the DSB will do as just a good of a job as the $400.00 Skimmer.
<Not... you would need a couple hundred gallon DSB to "do about the same good">
Another thing is before I only had a half of cup full of dark skimmate in my collection cup per week and now its every three days so I know I'm pushing the skimmer to its limit. I have always done maintenance on the skimmer, weekly water changes, run activated carbon, Chemipure and every so often PolyFilter pads. There is also 200lbs of rock in the tank that I think is enough and still allow the fish to have plenty of room to swim around.
<Much to consider. Bob Fenner>

DSB and reactor media
> Hi, Mr. Calfo, Here I am again. The following questions is bothering me a lot.
<No worries, my friend...>
> 1. Why is it a bad idea to mix some larger coarser grade sand into a 6+ inches DSB?
<Various grains of sand permit or deny diffusive action (osmosis, saturation or diffusion, etc). So a bed of coarse sand only will allow better penetration of oxygen rich water (which you do not want for efficient denitrification) by virtue of the large angular shapes of the sand media and the larger spaces between grains. It also traps more detritus but does encourage more amphipods. Fine sand, on the contrary encourages more microfauna (bacteria, tiny worms, copepods) and is better suited for the establishment of a larger colony (because of the increased surface area of the smaller grain sized) of denitrifying bacteria.
When all is said and done... we don't need coarse sand for amphipods because they will grow anywhere else easily (live rock, sump, refugium) and the trapping of detritus can be a nightmare to keep up with and in the typically poor current displays of so many aquarists leads to the crash of a sand bed unfairly blamed on DSB methodology. You want sugar fine sand if you are gunning for denitrification and it really needs to be as deep as possible (solid 3" minimum but over 5" is much better)>
> 2. I just bought some calcium reactor media by Dupla. The media looks like some crushed coral and shells, and I am sure they are. I have also checked out the calcium reactor media by CaribSea, and it too looks like crushed coral, but it is claimed to be aragonite. Why???
<Not all shell/calcareous media is aragonite. About 20% of the beaches in the Caribbean are said to be composed of aragonite... the rest are calcite. Just a different form of calcium carbonate but a big difference nonetheless. I have seen some studies about reactor media... not the least of which are reports from the notable aquarist/author/manufacturer Daniel Knop. Avoid shell and crushed coral at all costs. They are least effective and most likely to impart undesirable elements. Champion Lighting and Supply have an excellent bulk calcium reactor media that is outstanding. Do look into it. Let them know I suggested it if you like.>
> 3. Since aragonite and crushed coral look so much alike, how can we tell one from the other by their appearances? Is aragonite crushed SPS coral?
<We aquarists cannot tell visually. It is a molecular difference. The notable advantage is that it dissolves easily and at a higher pH. Calcite is tough to
dissolve. We must trust the word and reputation of the vendor along with the experience of fellow aquarists.
Many of my friends swear by the bulk media at Champion.>
> Sorry to bother you. Thank you for your time.
<No bother my friend, always a pleasure.>
> Sincerely Samuel

Deep Sand Bed
Cheers, Samuel! > Hi, Mr. Calfo, > > Your book is great. Mine is a bit worn now because > it > has been read a lot. Wow! Now that's a compliment. I thank you kindly and I am delighted to hear it! > > I am thinking of having a deep sand bed (6 inches) > in > my aquarium. Yes...6+ inches is my preference. What do you think of the idea of adding sand in an aquarium one layer (about two inches) at a time so as to allow the previous layer to mature and to be populated by the desired organisms and bacteria before adding the next layer? Definitely a problem as the intermediate stage of 1-3 inches in particular will struggle as a zone too deep to be sufficiently aerobic and not deep enough for anoxic activity. This is the root cause for many critics complaint about DSB methodologies... they don't put a deep enough sand bed for either strategy to succeed and the sand bed (at 1-3") becomes a dead zone and nutrient sink. > > I wonder if a one-time addition of 6 inches of sand bed will cause the lower portion of the bed to be too  much anaerobic and thus it will create hydrogen sulfate. Rest assured, a well maintained aquarium will have no such problem. I have moved many displays in the last decade that never ceased to amaze me... after years of being set up, the sand shoveled out of the aquarium looked like it was brand new! Sulfides occur from neglect of husbandry (poor water circulation in display, a skimmer that doesn't produce daily, overfed or overstocked with fish, lack of detritivores, etc). Some keys to success: all fine/sugar fine sand grains (never mix grades especially with course sand), always have very good water flow in display with minimal dead spots, over 4" must be maintained everywhere at all times, resist too many hermit crabs and rely on more gentle detritivores (White sand stars, sea cucumbers, etc). Gentle stirring of the sand on occasion is optional but may help some coral species (like Nephtheids). > > Thank you very much for your time. > > Cheers, Samuel Best regards, my friend. Anthony

Deep Sand Bed Clarification - Jaw Fish Questions
Dear Mr. C,
<<Greetings>>
Just curious as to your opinion on the sand bed debates. Dr. Goeman's recommends four inches of 1-2mm over a plenum. Dr. Shimek calls for 6-8 inches of sugar-size on the bottom of the tank. Bob seems to go for 3-4mm and 3-4 inches with or without a plenum. The hoipoloi have various strongly held and voiced opinions. I am at a loss, and my head hurts. Besides Advil, any suggestions? <<two Advil? Personally - really this is what I have in my refugiums - I would just do a sand bed as deep as is practical, with the finer sugar sands and as much liver rock as is practical. Plenums do work, but require more time to set up and the debate is whether or not the interstitial critters can move through the layers the way they need to or not. Four inches of sand would be fine.>>
Semi-related question: Approximately how much floor (sandbed, not living room) space does one allow per yellow headed Jawfish? <<I am not recalling, I do believe it's more than you might think... http://www.wetwebmedia.com/jawfishe.htm - one per system is what Bob says.>> like that No rush; at the rate I'm progressing my tank will be up in 2003.(And the whole philosophy will change again! Sigh.)
Thanks,
Pam S.
<<then again, it may not and you'll be well prepared. Cheers, J -- >>

Clarification on a Deep Sand Bed
Robert-
I really appreciate your quick reply. It was helpful, and I have decided to set up the tank before I go on vacation.
In your reply you said that the 45 lb Fiji rock and 60 lb sand sounded like too much for my 28 gallon tank. I was thinking the 45 lbs did sound like a lot, but the 60 lbs of sand was a figure calculated online for a 4" depth. Actually depending on the density of the sand it calculated between 50-65 lbs. Would 30 lbs of sand be enough to provide a deep enough sand bed? <<30# sounds more reasonable. I just went down-cellar and measured my 20L which is the same height as a 29 [if I recall correctly]. A 4" sandbed would leave you with roughly 7" of water. That's a little silly - perhaps/definitely overkill for a 29. It's one of the reasons that I'm not a big fan of ratios and patent answers. It's all relative to the size of your tank. Two to three inches would be a deep sand bed for a 29. Spend your money on a good skimmer and less rock and sand. Skimmers are just as important as important in the filtration game as live rock and deep sand beds.>>
Thanks Again
Jeff
<<Cheers, J -- >>

Clarification on Deep Sand Beds
Dear Jason:
Thank you for your response.
<<no problem>>
Could you please be provide a little more detail on your opinion regarding my desire to convert my sand bed to a deeper sand bed?
<<we are talking about converting your sump [taking out the bio balls] into a refugium here, correct? You simply add sand to it to the appropriate depth, preferably something very fine grained. You could do the same in your tank, but the purpose of a sump/refugium is to keep the beneficial critters out of harm's way in the main tank.>>
Thanks again very much.
John
<<You are welcome. Cheers, J -- >>

DSB Debate
Mr. Fenner, Mr. Moe, Mr. Farley and Mr. Shimek
<Anthony Calfo, author of the Book of Coral Propagation, in your service while our friend Bob Fenner travels>
I was hoping that you gentlemen could clarify what I believe to be misinformation regarding DSBs as the filter that made all other filtration obsolete.
<a great methodology, but not so absolute as it has been misinterpreted>
I have been involved with SW aquariums for about four years now and wanted to get your opinion on Deep Sand Beds.
<my pleasure on a topic that I am also interested in and espouse conditionally>
Basically my question centers around many "experts" on the net claiming that all one needs for *any* marine setup including FOWLR is LR and 6 inches of fine sand.
<not accurate or responsible for most aquarium systems with a moderate to heavy bio-load (right or wrong)>
They claim skimmers are obsolete and that mechanical filters should not house anything, but rather use them for circulation only.
<I personally would be inclined to not run most marine systems at all rather than go without a protein skimmer. I find them to be invaluable for most (some exceptions indeed, but we are assuming advice for the masses here who make mistakes like most of us, overfeed or overstock on occasion, etc)>
I have seen numerous posts by "newbies" inquiring how to set up their first system and the resident experts tell them no sump, no skimmer, no canisters. All you need is the LR and a 6 inch DSB.
<that is dangerous and irresponsible IMO to say to a newbie that does not have an adequate grasp of critical dynamics in reef aquariology to succeed with such advice/application thereof>
I would greatly appreciate your input on this matter. Pros, cons, is it bs, are skimmers obsolete and DSBs the holy grail for FO and FOWLR set ups ? etc..
<I personally prefer a DSB in most of my marine aquaria, but appreciate them for the biological diversity/microfauna that they yield and their support of denitrification predominantly. For nitrification and nutrient export I rely on live rock and protein skimmers largely and recommend it to most aquarists just the same.>
This seems to be an off shoot of the article by Mr. Shimek
http://www.reefs.org/library/talklog/r_shimek_090698.html
which is now being applied to FO or FOWLR setups with absolutely no other equipment. Best Regards, Nick Sahadi Friendswood, TX 
<Nick, thank you for forwarding this thoughtful and popular question. It sounds like we are in agreement. But the constructive dialogue of contrasting opinions is quite interesting and helpful nonetheless. With kind regards, Anthony Calfo>

Retrofit of a DSB and Protein Skimming
Hello there... it's been a while since my last question, and once again, I would like to thank you in advance for taking the time.
<You are welcome.>
My nitrates are at around 100, which isn't too bad because it's a FOWLR, but nonetheless, I want them controlled for the happiness of my fish.
<Good, it would be better for their overall health to have the nitrates lower.>
My 100G tank has a 40G Rubbermaid sump that holds a TF1000 protein skimmer. The main tank has about 90lbs of LR and only a 1" layer of fine LS. My family of fish include:
Naso lituratus - Naso Tang - 5.5"
Rhinecanthus aculeatus - Picasso Trigger - 3.5"
Balistoides conspicillum - Clown Trigger - 3.5"
Premnas biaculeatus - Maroon Clown - 1.5"
Diodon holocanthus Linnaeus - Porcupine Puffer - 3.5"
Here are my questions:
1) Can I simply add in more LS to turn my floor into a DSB? I was thinking about 3". I'm thinking of moving all the LR to one side of the tank, and adding the 3" of sand to one side of the tank, then moving the LR over on top of the new 3" DSB and repeating the process on the other side of the tank. Then I'd also eventually like to add in another 50lbs. of LR.
<I would add the additional LR but not sand. I do not like DSB with FO tanks. The sand bed can too easily become overwhelmed by the influx of nutrients from such greedy eaters as your fish.>
2) Do you recommend (I forget the brand name) that sand that comes in the sealed packaging "wet" and "live" or should I just get some fine aragonite and wait for it to become live?
<I always use dry sand and seed it with live sand from another tank I trust or with good quality live rock.>
3) I've never quite understood this... does a protein skimmer actually lower nitrates or does it just remove the dissolved organic compounds that eventually become nitrate (basically slowing the production of new nitrate)?
<The second answer, removes dissolved organics.>
Thanks again!!! - Eugene
<You are welcome. -Steven Pro>

Weight of DSB
Dear Whomever:
<Anthony Calfo in your service (having purchased 48,000lbs of fine aragonite at one point for my coral farming greenhouse!!!)>
I would love to put a deep sand bed of 6-8" in my new 220 gallon reef (only in planning stages). If I am estimating correctly, that amounts to about 700 pounds of substrate! 
<exactly>
Can a standard glass tank and stand handle that kind of weight? 
<absolutely... water is indeed heavy...almost as much as the sand in density>
I am having nightmares already. 
<try wine before bed>
Thanks for any advice.
<very welcome>
By the way, tell Anthony I love his book; quite practical information!
<I will...as soon as that fragment of his multiple personality returns <G>. Anthony>
Sincerely, Pam S.

Re: DSB & wet/dry questions
Thanks for the quick response. Is it a problem to have so many different substrates? What will the result be? How much sand would I need to fill the 125 (72x18x22) with 3-4 more inches of sand? Thanks!
<Please read through the Marine Substrates articles and FAQs posted on WetWebMedia.com here.
Bob Fenner>

DSB & wet/dry questions
Mr. Fenner,
<You got Steven Pro today.>
Just picked up a copy of your book, and have to say, very well written!
<I am sure Bob will appreciate your kind words.>
Enough flattery and on to the questions. Here is my setup. I have a 125 tank, 40 gallon wet/dry sump, AquaC Ev-120 Skimmer, and about 160 lbs. Of Fiji Live Rock. It is a new setup and I have had the Rock and the skimmer in place for about a week. I started this with the wet/dry in the system as my initial intent was to have a fish only but am drawn to the reef. So, here is my question, since I am still both cycling the tank and curing the live rock in my main tank, should I just remove all of the bioballs at once in the wet/dry and use it as a sump? Or should I remove them slowly. I don¹t think it matters as I have no animals to hurt from a spike of any kind.
<I would wait until the rock is done curing (ammonia and nitrite drop back down and maintain a level of zero). Then you can remove all of the bio-balls. Make sure you do not get another spike (unlikely), but best to be cautious before adding your animals.>
The second issue is of the substrate. I have about a 1/4 inch of crushed coral, about 2 inches of the Carib-Sea medium coarse Aragonite reef sand, and about a 1/4 inch of Carib-Sea Live Sand in that order from the bottom to the top. Is this OK? My impulse is to pull it all out and just go with about a hundred pounds of live sand and create a 4-5" DSB? Or should I go with about 3-4" of the finest dry aragonite and then top off with about an inch of live sand? Any thoughts or suggestions? Would you pull the current substrate, add to it, or leave it as is.
<I would add 4" of fine grain size aragonite sand and then place 1" of livesand on top.>
Thanks a million!!!!! Adam
<You are welcome. -Steven Pro>

DSB
Mr. Fenner
<Anthony Calfo in your service>
I have a 30gal tank with approx 45-50lbs of LR and a little LS covering the bottom. Until recently the LS was 4-5" deep, but I was having a problem with relentless hair algae. No matter how many H2O changes or LR cleanings, the hair would be back in a couple of days. Then with the last H2O change I noticed that the sand was just full of detritus so I removed the majority of it. Alas absolutely no more hair algae! I cleaned the sand thoroughly so that maybe it can be added back in the future. Is this something that you would recommend, or should I just leave well enough alone? 
<the sand was not your problem, my friend, as you know... it was the detritus. With enough water movement and sand sifters to keep the detritus in suspension, you would not have had the problem (nutrient export processes like a good skimmer would keep the churned nutrients from accumulating. So if you put the sand back in , be sure to have better water flow and sand stirrers. I'd recommends the DSB if you have a specific need for denitrification...wonderful>
Livestock: 1 False Percula, 2 Banggai's, 1 Emerald crab,1 Peppermint shrimp, asst hermits and snails. Would sand sifting stars
<yes>
and perhaps Nassarius (sp?) snails 
<modest...need many>
be enough to keep the DSB clean since I don't want any more fish at this time? 
<just better water flow then to help the skimmer capture the organics>
Thank you very much for all the help that you provide! Nathan
<kindly, Anthony>

Re: Sand Bed/ moving sand?
<<Not Bob, but JasonC doing a cameo - how are you?>>
Hi Jason-- I guess this was a way for Bob to go out and sun himself and you guys get the work. He is *so* smart! And also a way of getting the competent folk off WetWebFotos. :-)
(I'm sure soon you'll have some more people grabbed up. :-)) 
Anyway, here is a follow-up. The every loquacious des is at it again.:-)
<<<and JasonC again, greets.>>>
Anyway, my condo is now under contract! So I will be closer! <<good stuff>>
So is this closer to you too? <<eh?>>
>Remember this is a LR and dry goods move only-- much to Jason's disappointment. :-) <<you know it.>>
hehehe. There is talk of a pizza party, fish give away for assistance on taking down the tank. I don't suppose you'll be around?? :-) <<no, sadly, and I also already have a coral beauty so...>>
>Also I have thought about a DSB but gosh even 3 inches is high on a 40 gal!! I think Anthony says that between 1-2 inches or so is actually dangerous, not a good thing.
Well is that what he says, I can't seem to locate it?
<<Bob, Zo, and I are were just discussing this... I know Anton. is adamant about this but it sounds a little funny on it's face, "This much sand is good, and this much sand is good, but anything in-between is dangerous." Will have to ask him about that. Certainly a lot of variables - substrate size, tank content, etc.>>
><<what is the object of this exercise? Just thinking the most common use of the DSB [Deep Sand Bed] is for natural nitrate reduction.>>
Having lots of little critters in there and not vacuuming. <<Ahh... well, you should get some good critter production from your refugium.>> Also better pH balance with more fine grade sand. <<ok>> I mean that's my idea. <<and it's not a bad idea. You could however encourage the critter growth with a larger sized crushed coral sand bed, that isn't particularly deep. They just need a place to hide/breed.>>
Since I have grown algae in the Ecosystem/refugium nitrates aren't really a big issue. <<and that was my earlier point, question.>> I get dentrification from the Ecosystem. <<amen>> In some ways it is a DSB. <<'zactly>>
>Hasta later your amiga,
--des/Jane
<<Bon giorno. Cheers, J -- >>

Sand Bed/ moving sand?
Hey Bob,
<<Not Bob, but JasonC doing a cameo - how are you?>>
(Or whoever might be answering for him). Glad you have somebody to assist you now. I've also gotten a kick out of all your exploits, real or imagined. <<is some funny stuff, indeed.>>
:-)
Anyway, my condo is now under contract! So I will be closer! <<good stuff>> This is a threat and a promise. :-) <<oh?>> Anyway some questions about the sand bed. I went over your answers to me in JULY. And I still have questions. What a shock! :-)
Remember this is a LR and dry goods move only-- much to Jason's disappointment. :-) <<you know it.>>
I am not moving anything by car, so this all would be in a box on the van or not at all. I am thinking I will move the LR and buy some more and add to it to give it new life. But what about the sand? I maybe have a 1/2 inch to 1 inch sort of medium fine aragonite. Will wetting it and putting it in an insulated box maybe inside a plastic bag
retain any useful life? <<I think so, yes - is how it is shipped, stored.>>
Also I have thought about a DSB but gosh even 3 inches is high on a 40 gal!! I think Anthony says that between 1-2 inches or so is actually dangerous, not a good thing. I was thinking of 2 inches, but maybe not.
(I guess that isn't exactly deep-- but it's sort of relative.) I realize that some folk will put 3-4 inches on a forty but it cuts down on LR space, water space, and so on. <<what is the object of this exercise? Just thinking the most common use of the DSB [Deep Sand Bed] is for natural nitrate reduction.>>
Your friend,
--des/Jane
<<And yours as well. Cheers, J -- >>

Re: Sand Bed/ moving sand?
Hi Jason (or whoever). Yet *another* des/Jane follow-up. ;-)
<<okies>>
>hehehe. There is talk of a pizza party, fish give away for assistance on taking down the tank. I don't suppose you'll be around?? :-) <<no, sadly, and I also already have a coral beauty so...>>
I suppose, and everything else I have as well. (or that I am selling). You don't REALLY want to come. :-)
<<sorry, as soon as I get home they're going to clamp on the leg irons.>>
>
> >Also I have thought about a DSB but gosh even 3 inches is high on a 40 gal!! I think Anthony says that between 1-2 inches or so is actually dangerous, not a good thing.
>Well is that what he says, I can't seem to locate it?
><<Bob, Zo, and I are were just discussing this... I know Anton. is adamant about this but it sounds a little funny on it's face, "This much sand is good, and this much sand is good, but anything in-between is dangerous." Will have to ask him about that. Certainly a lot of variables - substrate size, tank content, etc.>>
Well so much is supposedly not anaerobic enough or something? Gosh I am confused. I glad that more experienced folk than me are confused. :-)
<<I wouldn't say we are confused, just skeptical, how's that?>>
> ><<what is the object of this exercise? Just
>Having lots of little critters in there and not vacuuming.
><<Ahh... well, you should get some good critter production from your refugium.>>
Yes, but they usually stick in the water column or seem to. I still vacuum the substrate. I don't have lots of worms. I think mostly pods and that sort of thing. <<takes a little while to kick into fourth gear.>>
>better pH balance with more fine grade sand. <<ok>> I mean that's my idea.
><<and it's not a bad idea. You could however encourage the critter growth >with a larger sized crushed coral sand bed, that isn't particularly deep.
>They just need a place to hide/breed.>>
I thought that larger coral sand was less good for pH?
<<oh, and it is - it's good for a lot of things.>>
Thanks my friend. You guys are doing a GREAT job!
<<well thanks. Cheers, J -- >>
--des/Jane

Re: Sand Bed/ moving sand?
Hi Jason,
A clarification please:
Re: critters
>Yes, but they usually stick in the water column or seem to. I still vacuum the substrate. I don't have lots of worms. I think mostly pods and that sort of thing.
><<takes a little while to kick into fourth gear.>>
Uh, do you mean to be patient? Would it help to add critters i.e from inland aquatics or somewhere else? And if I add them should I put in the sand bed or refugium?
<<Patience is a virtue worth striving for in any endeavor. As for the live sand starters, or detritivore kits, sure no harm done from the addition.>>
>I thought that larger coral sand was less good for pH?
><<oh, and it is - it's good for a lot of things.>>
About larger grain coral sand:
What do you mean? Do you mean that it is equally good for pH or that it isn't as good. <<is pretty much all the same stuff and would be more than adequate as a pH buffer, etc.>>
Thank you (I hope I am not being too much of a pest or at least more than usual :-)) <<Alrighty then... ;-) no pests here.>>
--des/Jane
<<Cheers, J -- >>

Deep Sand Bed... on the right track
Hello Anthony-
<greetings friend>
Thank you so much for your prompt response. I am coming straight home after work each day so I can check on the kids in the tank.
To answer your questions.. And I feel a e-mail slap on the hand coming.
<nope... I am much kinder and gentler on medication>
I have 1 Naso tang (Clyde), 1 Sailfin (Hapu),1 regal blue (Gwenivere) and 1 yellow (Sanchez).
<I love the names!>
And a few of my original set up damsels from 5 years ago. A 55 gal tank The Naso is growing quite fast (is approx 6-7 inches now) was MUCH smaller when I picked him up 4 years ago but and I am eyeballing a new 90 gal tank.
<yes... please do. Better yet, consider a lower and longer 100 gallon tank (or any 6' new digs instead of another 4 footer which does not offer much more swimming room, just more water>
He is such a beautiful fish.
<agreed.. magnificent! $ years is good... keep going!>
They are all beautiful. Regal has developed a bit of hole-in-head.
<common with this ultra strict herbivore...needs near 100% green diet!>
I now soak the food in Zoë and Zoecon. Hope it helps.
<maybe... but do add a greater variety of greenstuffs and/or customize your own home-made food as described in Bob's CMA book>
The yellow seems like it is catching the brunt of my current problem. The poor fella is puffing and just swimming back and forth and will not eat(3 days now). All others have kept up a little bit of an appetite. And their respiration seems like it has slowed a bit since yesterday. But the nitrates are still in the 75-100 range.
<keep doing proper water changes... adding extra aeration wouldn't hurt too. Resist overfeeding which lowers dissolved oxygen>
The substrate is about 1/2 inch in the front and increases to about 2 inches in the back. 
<dangerous in my opinion. Too thick to be aerobic but not thick enough to be helpfully anoxic. Just dangerous and the reason why so many other reefers have inaccurately faulted "deep" sand beds. The rule stands at 1/2 inch or less, or more than three inches (I use five inch minimum for denitrification>
And is usually 2 inches around and big rocks (for support) Around these rocks (in the deeper coral) is where the large quantities of
dark green or gray matter filled the hose and vacuum.
<gray can be scary>
I dig down until I hit the bottom and then move around a bit.
<shouldn't be necessary with adequate water movement and sand depth in tank... also disturbing to microfauna if too aggressive>
When I clean the tank I use the siphon and force it down till I hit the bottom of tank. And just move all around the tank. I would call it
aggressive. One guy at the LFS seemed much more knowledgeable than the rest and was the only one who thought that I might have let out a lot of noxious material (just like you suggested). I think I may have explained his suggestion wrong.
He suggested that I remove about half of the larger crushed coral. Push the rest of it against the back wall and slope it towards the front, stopping about in the middle of the tank (a slope). Then add about 2 inches deep of aragonite (1-2 mm size.) and slope that towards the front, stopping about 3/4 of the way from the back. Then add 2 inches of .5-1.0 mm aragonite and taper it off till it is about 1 inch deep in the front. And create circulation that would move the water from the top of tank, down the front and back towards the back of the tank and that it would move through the substrate and in the deeper portion along the back is where the nitrates would be eliminated.
<the intent is good, but the execution is flawed in my opinion. It does not serve the greater good to leave any coarse material (crushed coral) behind... it is just a nutrient trap and source of pollution. It is not even a functional buffer at this point having been covered with organics. Furthermore, the mixing of grades of sand is not necessary or helpful if screened, and not successful without it. Don't bother at all. If you want denitrification, use all fine aragonite at more than three inches of depth. Otherwise, use any grade of sand that looks good at 1/2 inch depth. The sloped bed, quasi-denitrification idea may not work as hoped with good circulation (O2 penetration) and movement of the pile>
Then get a few sand sifting starfish and just siphon OFF THE VERY TOP of the substrate at cleaning time.
<much agreed>
I was considering swapping with the finer aragonite so that I could let a starfish have a buffet underground. 
<nice idea>
If I put just a thin layer of the aragonite, 1-2 mm size, could I let a sand sifting star loose in there?
<no mixing...above reasons>
I now only have the brittle stars and shrimp for cleaning the bottom.
<a good start but need more>
Is there a short term solution for lowering the nitrates until I can get the substrate problem fixed? ? 
<dilution is the solution to pollution>
I am not sure how long they can all hang on while I get my act together.
<honestly, you are considerate and it sounds like you are on the right track!>
They are stressed enough right now without me being "all in their business". I have changed 20 gal of water in two days. Will changing more cause a problem? I was planning on 5 gal every other day until I figure this out or until the nitrates drop.
< a necessary evil and almost no stress if done properly>
My pH has dropped into the high 7 range in the last few days after the water changes. Should I correct it or let things mellow out a bit?
<way too low... water changes should be bringing it up. Find out why (test source water, aerate tank heavier to drive off CO2, etc)
It is not a reef tank nor will it be heading that way. I just like the idea of things happening in a more natural way. The idea of the deep substrate naturally removing the nitrates sounded good.
<very cool and agreed>
Wow.....this post is longer than the last one. I will try to leave you alone after. Thank you Anthony, for your expertise!!!!!! Dennis
<no trouble.. my pleasure, bud. Anthony>

DSB questions
Hey Anthony, Steven, Bob (in absence)...
<Hi ho, hi ho, answering FAQ's I go (everybody whistle). Steven still here.>
So, I've got this 55 gal flatback hex tank, set up as follows...
3-3 1/2" DSB, CPR Bak-Pak II (using a tiny bit of BioBale for bubbles), 1 802 PH, 1 402 PH, 4X55W PC lighting.
3 colt coral, 1 bubble, 1 frogspawn, 1 recently fragged Sinularia sp. (finger), asst. 'shrooms, pulsing xenia, 7 month old sebae anemone
1 yellow tang, 1 tomato clown, 1 small grey Poma angel, 1 soon-to-be-gone-if-I-can-catch-it striped damsel, 1 coral banded shrimp, 1 cleaner shrimp, 1 sand sifting starfish
OK, now to the questions....My tomato clown loves to dig. He has managed to dig an area near the anemone that comes w/in about 1" of the tank bottom. If I leave this alone, he doesn't dig anymore, but is this a dangerous situation due to the thinness of the substrate in that area? If I try to level the area, he just digs it out again, with a swirling cloud of sand...Whoosh.......By continuing with the smooth and dig method, am I doing more harm than good? I was thinking that I may be releasing wastes, etc. into my system that were being broken down in the DSB.
<I have the same problem with my maroon clownfish and I think Anthony did, too. It all depends on how annoyed you are by it. Anthony was considerably more determined to smooth the sand than I was and did it everyday. I think he eventually gave the fish away to his brother-in-law out of frustration. I let my maroon do what he wants. This hobby is supposed to be relaxing.>
Next...I was thinking about adding a bit more sand to my system, preferably some from other systems (diversity and all). If I were to add an additional 1" or so on top of my current DSB would that be harmful to the current critters, or likely OK?
Currently my NO3=0, NO2=0, PH=8.4, Amm=0, Alk=13dKh, Cal=375. Maybe I don't really need to add the sand, just do some LS swaps for diversity? What 'chu think?
<Swapping some LS could be dangerous for your tank. You would want to be fairly confident that the tank you were getting sand from was well maintained and disease free. You may want to purchase some critters from one of the various online e-tailers that sell these clean up crews.>
Have a blessed day guys, and keep reefing!
Jason Harris

Sand Bed
Dear Anthony, Steve, or Bob:
<You got Steve today.>
Let my start by saying that Bob's book has become my defacto source of marine fish keeping info. I read as much as I can from as many sources as possible, but I keep coming back to the CMA! You guys are truly an inspiration for me and my efforts in this hobby! My entire outlook on aquatic husbandry has changed as a result of CMA and WWM. Everyone who is serious about keeping marine animals needs to use this resource!
<Glad to hear it!>
Well- here's my question... I've seen a lot of correspondence in the daily FAQ's about sand bed depth, and I think I overdid it just a bit. The depth is about 3 inches, and I use Aragamax sugar-sized sand from CaribSea. I established a 150 gallon FOWLR system about 6 months ago. The system has a ETSS Sump and Evolution 750 downdraft skimmer. At your suggestion I have established a refugium in the sump with an assortment of macroalgae, lit 24/7 by a small fluorescent.
I have a modest fish load, and the main aquarium has about 150 lbs of high quality Fiji live rock. I have fantastic coralline growth on the rock and on the back wall of the tank. CSL 4x96 CF lights provide plenty of light.
Nitrite and Ammonia are zero, Calcium is 350ppm, alk 2.3meq/l, ph 8.4, Phosphate 0.5ppm, and Nitrate has been steady at 10.00ppm. I do regular small water changes twice weekly. Basically, everything seems ok (I'd like to get the nitrate down to 5.0ppm or lower, though).
My fear is for the long term. After reading your FAQs and other WWM resources it's apparent that over 2 inches of depth may not be a great idea for long term management. Am I being paranoid, or should I reduce the depth to about an inch or less? Will there be any short-term toxic effects on my inhabitants if I reduce the depth at this point? Or, is it ok to keep the 3 inch depth with regular sand bed siphoning and maybe more "sand stirrers"? Sorry for the length of this email, but I am really concerned about the long run, and I hope that I haven't put my precious animals on a slippery slope to long term demise! Once again, I greatly appreciate all that you do to make our hobby so gratifying!
<I have not read all of the info on the site, it is a bit overwhelming, so I cannot speak to the FAQ's you spoke of. I will give you my opinion and I know Anthony is of the same mind set. I will always use a Deep Sand Bed in a reef tank, but it must be 4-6" deep. Less than 4" is not beneficial and can be disadvantageous. I would also always recommend purified water (RO, DI, etc) when using a DSB. It does you no good to have nitrate converted to nitrogen, but have a buildup of phosphate from your source water (Cyanobacteria problems, interference with calcification, etc). In a fish only tank, I would probably siphon off some of the sand to bring it down to 1" or less.>
Regards, Scott F.

Sand Bed follow-up
Steve-Thanks for the FAAAST reply!
<Just wait until you get this one.>
I will definitely reduce the sand bed to 1 inch or less- do you think there will be any negative nitrate/nitrite/ammonia ramifications if I do this all at once, or is it better to reduce the gravel bed say, one inch at a time?
<Possible nitrate ramifications, but can be counteracted by aggressive protein skimming, stepped up water change schedule, and use of purified water (RO, DI, Kold-Sterile). Probably no effect on ammonia or nitrite. All of the above regardless of slowly removing versus all at once. I would be a little lazy and remove some over several water changes. -Steven Pro>
Thanks again Scott F

Substrate Follow-up
Hi Steven, Thanks for the super fast reply.  Sometimes this technology stuff isn't so bad.  If I read your reply right, I'm okay with using my current substrate at a depth of less than 1 inch, as this future tank will be fish-only.  I also plan on adding a cherub (pygmy) angel and chain link moray to the collection.  Do you think the 1" substrate will be able to handle the nitrate load?
<Sorry, I didn't specifically mention that.  No, a bed of sand that thin will do nothing for denitrification.  For that I suggest the use of purified water (RO, DI, Kold-Sterile), aggressive protein skimming (collection cup filled with skimmate the color of hot tea to coffee several times weekly), and regular partial water changes.>
Or would I be better off going deeper with finer sand?
<I believe a DSB can be overwhelmed by a heavy fish load in a lot of fish-only tanks.  Considering the light fish load you currently have and your intended additions, you may want to opt for the DSB.  The only other consideration is will your future moray create a sandy mess when he goes slithering around.  -Steven Pro>
Thanks again. Jason B
ps. Love this website and all the work you guys do. There isn't a whole lot of interest or information about marine/reef keeping up here in Maine. Only one "real" fish/reef store and a few others that really don't try. 

DSB in main tank
Hi Bob!
Why do you recommend placing the DSB in a sump vs. in the Display tank?
<Yes... either>
I've searched your site to no avail for the answer (the DSB Article is a blank page, and it's not addressed in the FAQ's).
<Needs to be written, added, thanks. <Is now> Read these files on refugiums: http://www.wetwebmedia.com/refugium.htm and beyond>
I am (slowly) setting up a 92 corner tank-the sump will be a 20 gal.15"dia. x 24"h Hex (or, if I could house an in-sump skimmer, maybe two, one for a refugium w/ DSB & macroalgae and one for equipment ---those are all that will fit under cabinet). Do you feel it would be worth it to include a DSB with such a small footprint?
<Mmm, yes... and perhaps a good hang on skimmer would do here... My selection input on WWM.>
Thank You! Erik Nelson
P.S. Saw a "Yellowtailed Moray" the other day @ the LFS. It gave me the "eye". Any opinions on this species? I know you recommend the non-piscivore(?) eels, but I really would like to keep cleaner shrimp alongside one.
<Mmm, maybe take a look through our coverage on muraenids: http://www.wetwebmedia.com/morays.htm and fishbase.org
Don't know this common name.>
P.P.S. My wife says that eels "turn her on". WOW!
<Wow indeed! Be chatting, Bob Fenner>

Refugium, Deep Sand Bed, and Diving.
Hi Bob,
Maybe you can enlighten me on a couple of things. I have a 90 reef tank mostly LPS and SPS with about 220 gallons total system water. I set up a separate plenum refugium in a old 70 gal. (48"x18") about 2 months ago. I followed your illustration and info on wetwebmedia.com, lots of great help from the FAQ. I have a problem, I bought too much substrate (CaribSea "special seafloor grade. 1mm dia.) What I would like to do is add this gravel to my display tank that has about 1" crushed coral already in it.
Not to the whole tank, but around the front, sides, etc. I don't want to take everything out and start over. Too much work. But with the added substrate I could make a deep sand bed about 4-5" deep about 6" wide (between the front glass and the LR.) Is this a good idea? 
<Mmm, maybe... you realize it will all be getting mixed together... about the same depth... over time>
I can't seem to find any info on people experiencing with a deep sand bed AND a plenum.
Your insight would be much appreciated.
<Both can work together... better than one apart from the other IMO/E>
On a side note, I just got certified PADI and I'm leaving for the Cayman Islands next week for a week of dives. :) You have any "favorite spots" I should check out? 
<There are so many... will you just be on Grand Cayman? Do you intend to just use one dive agency? You only have a week... the place isn't all that big, but IS huge underwater... I'd just go, trust the local folks who are showing you about... There's not too great a variability in the biological make-up (nor much in the topography) all about the island. Hopefully you are intending to make photos... Oh, and do read over about the Caymans on the Web. A very popular dive/travel location.>
It would be a nice and educational change to see reef creatures in their natural environment. 
<Definitely>
Keep up the fantastic website! Any plans for a new book?
<Always working on such. Next... a Pond Pocket Guide! Don't groan. Things could be worse... be chatting, Bob Fenner>
Brad Stefanko

Re: Refugium, Deep Sand Bed, and Diving.
Whoa fast, fast response. Thanks for your help! I have a follow up regarding my refugium. Is it possible to raise cleaner shrimps in a dedicated refugium?
<Yes>
I wish I had more that a week in Grand Cayman. I have seen all kinds of wonderful pictures of reefs there. I don't think a week is enough either.
I know I am going to work in "Sting Ray City" experience. 
<A "standard">
The dive agency that we are using is Ocean Frontiers. I have bought a camera and hope you use lots of film! I do have a trip planned for Fiji in June '02 I assume there are great dives sites in Fiji also.
<Yes... am off to Taveuni 11/27... Supposedly heading back in May... Maybe we'll meet up there in June!>
As always, warmest regards
Brad
<Be chatting. Bob Fenner>

DSB
Hi Bob -
I converted my crushed coral substrate to a DSB yesterday in my 120 established tank- used Southdown sand that I seeded with the CC from the existing tank (made balls with nylons).
Two days later, the water is still cloudy. Is this normal?
<Yes>
How long will it take to settle?
<A few days to a week or so>
I have a sand stirrer/detritivore kit coming to me on Wednesday, and plan to add it after the lights go off - any further suggestions?
Robb
<Mmm, would have been better to add these organisms a week or so later. Can you accommodate them elsewhere? Bob Fenner>

Deep sand bed
Bob, your opinions please.
A deep sand bed is a given, 
<Perhaps in this scenario)
the question is "to plenum or not to plenum"?
<Pros, cons>
Siphoning live sand to clean detritus. Some "experts" say it removes too many valuable critters, the reason for the live sand to begin with. (?)
Any opinion on Marc Weiss's reef products?
<"Emperor's New Clothes">
Calcium reactor, out of the budget. Kalkwasser to much trouble. To keep up calcium levels and alkalinity, what in your humble opinion are the best additives to use?
Constant or sporadic use of carbon in a reef system?
<All this posted on the WetWebMedia.com site. Please use the Indices, Search engine there>
Let me ask you one more question since you're published in aquarium magazines. The very same magazines where all the Q&A forums are constantly filled with kids questions or just plain stupidity. (Sorry to be so harsh)
<No need to