High nitrite and nitrate 4/22/08
I have a 54gal corner marine aquarium, fish only setup. I transferred fish from an old tank to this new setup, which I now know was a mistake since the tank had not properly cycled.
<The root of your problem most likely.>
All fish died except a yellow tang and a blue damsel.
<Honestly, the tank is too small for a tang.>
The tank has now been running for a month with a Megaflow sump filter system. I used BioZyme to help start the biological filtration.
<Dried bacteria cultures are not worth much in my opinion.>
My problem is I cannot get rid of nitrites and nitrates.
<Nitrate buildup is a common problem in FO tanks, no deep sand bed or live rock for nitrate reduction so lots of water changes are necessary. Nitrites could be due to the tank still cycling, not enough filter media, or overfeeding. In this case I would guess the tank is still cycling.>
Ammonia was high but is now back to zero. All other parameters are in good range except for the nitrite and nitrate.
<Sounds like the tank is still cycling.>
I have done 2 sets of 15 gallon water changes a week apart.
<Needs more, nitrite is very toxic.>
I am starting to get some brown algae growing on the sand/glass.
<Normal for a new tank.>
I am just at my wits-end. I cannot get rid of the nitrates.. What do I need.
<Nitrates? Water changes is the only thing to remove them. Nitrites require the proper bacteria to be cultured.>
Many thanks.,
<Welcome>
<Chris>

Fish Only Tank With Algae Issues! – 06/07/07
I recently set up a custom acrylic aquarium for a client. It's a 1500 gallon (approx) racetrack tank built by ATM in Los Vegas.
<Sounds sweet!>
The tank has gone through the initial cycle (setup early Feb).
Fish at the moment consist of:
1 Vlamingi Tang
1 Desjardin' Sailfin tang
1 Regal Tang
approximately 7 Green Chromis
2 Blue Damsels
1 Royal Gramma
2 Percula Clowns
Inverts are approx 40 Cerith/Nassarius snails and 1 unknown type of Hermit (brown).
The filtration consists of the overflow filled with bioballs, an incredibly huge wet/dry, UV sterilizer, double canister with 50 micron filter, and a useless skimmer that either produces nothing or overflows within 2 minutes. There is no in between.
There is also about 60 lbs of live rock in the tank (more will be going in tomorrow).
Within the last week, large amounts of brown algae have started covering pretty much everything within about 4 days of cleaning. The side walls are easy, and the sand is being turned not too bad by the snails (another 100 are going in tomorrow), but the coral insert is being overrun.
<Well, there may be some issues that are occurring that can prevent, or help diminish the algae problem if addressed. First, review the maintenance procedures for this system. What kind of source water are you using? Untreated tap water often contains excesses of compounds and nutrients that can stimulate algae growth, particularly the nasty brown varieties. If you're not already using RO/DI water to prepare your seawater, do consider switching. Check that source water for phosphates, nitrate, and silicates, all of which can contribute to algae woes if left unchecked. If you are constantly changing water (a good practice), but using untreated water (a bad practice), this simply re-fuels the algae each time. If you are already using RO/DI treated water, do check your membranes to see if they need replacement. Also, consider the use of chemical filtration media, such as activated carbon and/or Poly Filter, to assist with the removal of organics. If the protein skimmer is ineffective, you really need to replace it with one that is. Protein skimming is vital, IMO, particularly in a fish only system. You need a skimmer that is both productive and consistent. Wet-dry systems, although effective, tend to accumulate nitrate because of their high efficiency. Water changes become more vital in a wet-dry filtered system. I'd consider yanking the bioballs at some point and letting the live rock do the "filtration". You may need to add more live rock, particularly in a system of this size. Another thought- replace that mechanical filtration media frequently, or it will simply become a nutrient sink as it traps debris and detritus if left unchecked for extended periods. Every couple of days is not too frequent, IMO.>
My client really doesn't want to see the algae on the resin corals (it's the centerpiece for his entire entertaining area) and would like it cleaned up ASAP.
<I can understand that.>
What recommendations do you have for cleaning it naturally (by critters) or an easy way to get to it manually?
<as above- you really need to address the root causes of the algae outbreak, and attack the problem with aggressive nutrient control and export processes, as outlined above. Another thought: Is it possible to install a refugium somewhere in the system where you can grow and harvest competitive macroalgae? Refugia are an excellent adjunct to FOWLR systems.>
I'm not positive on the number of snails that I should even be looking at in a tank this size. If you have recommendations on numbers and species it would be appreciated, or any other tips for looking after a tank this size.
<Well, if you go by a "snails per gallon" mentality, it should be hundreds.>
I'm currently doing a 20 gallon water change every two weeks which is probably a bit on the low size at least when the tank is stocked fully.
<I think that you should be doing at least (gasp) 150 gallons every two weeks...Large tanks still should receive 10% water changes, IMO. Expensive, but it goes with the territory.>
There are no tanks anywhere near here like this one, so I can't just go check out another one to get ideas. The manufacturer has been frustratingly absent on after sales service the moment they got paid.
Regards,
James Foley
Thunder Bay Aquascapes
<Well James, it's a tough, yet solvable problem. The system has some issues that can be addressed with hardware modifications/additions. Also, working on some of the aforementioned husbandry issues can help, too. With a little testing, tweaking, hard work, patience, and the passage of time, this tank can indeed become the showpiece that the owner intended. Do make liberal use of the resources on the WWM site for more ideas on nutrient control and export, husbandry, and hardware. Good luck! Regards, Scott F.>

Fish Only Tank With Algae Issues (Pt. 2) - 6/7/07
Thanks for the very prompt reply Scott.
<You're quite welcome!>
The source water is tap. We're blessed with good water here. No nitrates, phosphates, silicates, TDS about 100ppm. I only use RO in my 130 reef. All other saltwater and reef tanks are just tap, and no algae issues in them, so I'm pretty sure it's more the setup than the water.
<Okay.>
I'll be calling ATM again today to try and get the skimmer working. It's plumbed into the system, so I'd much rather figure out how to get it working if possible. Changing it would be a royal pain. Underneath the stand looked
very spacious until the drywall was put around it. :)
<Lovely! It could also be an issue of where in the system the skimmer is located. If it's not situated where it will receive "raw", unfiltered water, such as from a surface skimming overflow, then it may not be set up for optimal performance from the get go.>
About how much live rock should I be looking at for a final amount?
<I don't buy into the "X" amount of rock per gallon idea. It's really a function of what you're trying to acheive. In a 1500 gallon system such as the one that you describe, it's entirely possible to get away with a relatively small quantity of rock (200-500 lbs, as you're contemplating).
I was thinking in the range of 200lbs in the actual system as I'd like to keep sand area free. It looks quite nice with large sandy area.
<Agreed. I like the open areas, myself...I've never been a fan of the "rock wall" aquascaping mentality that is so common in the hobby.>
I have no problems adding a ton to the sump though. I will consider switching out the bioballs in the future. This is my first fish only system. I'm much more
familiar with reef systems using complete natural filtration.
<The good news is that you can apply similar techniques to FOWLR systems with a great deal of success. The big downer here is the apparently flawed protein skimmer. A skimmer in a fish-only system is a vital component, and it's proper function is vital to long term success. You really want to acheive a daily skimmate production to keep water quality high and dissolved organics to a minimum. The rock will act as your biological "filter".>
Unfortunately the company tended to ignore my phone calls during construction, so I wasn't sure what the system was going to look like when it showed up.
<That's a bummer...>
There is enough room under the stand that I could probably put in a 30-35 gallon aquarium with Chaeto in it. Would that be large enough? It shouldn't
be too hard to get it in there.
<Hey, any type of refugium setup is better than nothing. With good lighting and regular harvesting of the Chaetomorpha, you can achieve some nutrient export.>
I'll shoot for around 500 snails and see how that works. Can you think of a species that would be more inclined to cruise over the coral inserts than others? The Cerith actually spend more time than I would have thought on the
glass. I'm used to them staying near the bottom of the tank.
<Interesting. I like Trochus and Turbo species, myself.>
I'll also start increasing the water change (I was aware of how large they'd have to be when stocked, even if I didn't want to admit it, that's more water than my 130 reef tank contains) amount and try some chemical filtration.
<Excellent practice. The higher volume water changes are really necessary from the start, IMO. Chemical filtration is a great idea.>
What are your thoughts on Seachem's Purigen? I started using it myself yesterday in my livestock tanks, but don't have results just yet. :)
<It's a great product if used as directed. I really like SeaChem products. You should also consider Poly Filter pads from Poly Bio Marine. They are another excellent chemical filtration media that is very effective.>
Thanks again for the replies.
<Glad to assist.>
I'll start looking into making changes tonight when I meet with my client. I'll also be doing a complete test on
the system tonight as well, so I'll get back to you on that later.
<Hope to hear how it turns out!>
Regards,
James Foley
<Best of luck, James. I'm looking forward to a happy ending for you and your client! Regards, Scott F.>

Fish only with live rock and Bristleworms   12/28/06
Dear Bob,
<Hi Steve, Mich with you tonight.>
I searched your web site looking for information relating to my aquarium, I have a 125 Sea Clear system II fish only tank part of the live-stock includes a Copperband Butterfly (read somewhere that he will eat Bristleworms).
<Sometimes.>
  Do Bristleworms cause any trouble to FO tanks?  
<Generally no, unless you have a super big monster hanging out in there unbeknownst to you, even then questionable need for concern.>  
I plan to make a homemade contraption to rid of these pesky pests, but again, not sure if its a huge concern to the fish.
<No worries, they are not really "pesky pests".  They are harmless to healthy animals, act as beneficial scavengers, and should be left in the system.>
Thanks.
<Welcome!  Mich>
Steve

Green Wolf Eel Blenny & Snowflake Eel  11/16/06
Dear Mr. Fenner,
<Erin>
I am new the Marine Aquarium hobby (~1.5 years) and your book, The Conscientious Marine Aquarist, has proved to be an invaluable resource for me.  I apologize for bothering you, but wondered if you could offer me some advice.
<Sure>
Thus far, I am guardian to a small, fish only, 30 gallon tank with a total of 4, so far very healthy fish.  Due to my inexperience and the costs associated with obtaining proper equipment, I have thus far resisted the urge to "upgrade" to a larger system.  However, I was recently offered a 90 gallon tank for free by a friend
<A friend indeed!>
who no longer has time to care for her 2 large tanks.  The tank has been slightly neglected and has a thick growth of hair algae, but otherwise it is in good shape with proper lighting, skimmer, filters, and powerheads, etc.  It is a well established tank that she has had for roughly 8 years.  My only real hesitation is that its inhabitants are a beautiful Snowflake eel that is probably 18-20", a green wolf eel blenny (I hope that's that accurate designation)
<Congrogadus... actually a Pseudochromid, a Dottyback... but goes by a few common names... this is one>
which is probably 12-15", an 1 large trigger.  They are all beautiful, and I do not want to take them on if I will have difficulty keeping them as healthy as they appear to be.
<I see>
Can you please advise me as to how difficult these creatures are to maintain, and if a beginner like myself will be adequately able to do so?
<Mmm, should be fine as they are now... having grown up with each other... However, you will likely find it difficult to add much other livestock here. I would "take on" as is for now... and later consider whether/when you're ready to possibly trade in these fishes for another adventure/experience>
Thank you very much in advance for any insight that you can offer.
Erin
<Welcome. Bob Fenner>