- Planning Stages and Questions, Questions, Questions -
Good morning everyone!  Thank you for such a great resource.  Too great!  My head is about to explode from information overload.
Anyway, I'm planning a reef tank / Palau biotope for my office.  I inherited a 95 gallon corner hex tank.  I've attached a diagram of the tank from above.  I read Mr. Calfo's article on a closed loop manifold and have decided that is the way I want to go.  (my design for that is the grey part in the attached image).  After reading a lot, I changed my pump choice for the closed loop system from a Iwaki WMD20RLXT (540 gph) to a WMD40RLXT (1200 gph).  Seems like a lot, but hey, more is better, right? <In the case of circulation, yes.>
So, my questions...  Due to the non-standard shape of the tank, I've designed 8 outlets.  I initially decided on 3/4" PVC, but think I should go with 1". Too many outlets? <I don't think so.> Correct diameter pipe? <3/4" might be better around the rim of the tank as should keep pressure consistent across the nozzles. Would still plumb up to the manifold with 1". Would encourage you to experiment with freshwater before filling with salt. This would allow you to swap out sizes if 3/4" doesn't work.>
Also, lighting.  I'm planning on a few fish (big list, trying to whittle it down), soft corals and mushrooms.  Since the aquarium is 24" deep, I am thinking I need MHs (although I really don't want to). <For soft corals and mushrooms, you don't need metal halides.> The problem is how to arrange the lights in the built in hood for the best coverage.  Is one 24" fixture perpendicular to the display area enough? <Yes, should be fine.> (assuming several lamps, adequate intensity, etc.)  What about the back half of the tank? <Are you going to be viewing this area?> I could probably put in a small fixture that runs perpendicular to the main fixture in the back half of the tank. <You could, would not harm anything if you did.> Any ideas? <Sounds fine to me.>
Also, June IMAC in Chicago.  I live there.  This is an invitation to dinner for any of the WWM crew that's going to be there. <I will not be attending IMAC but this will be posted on the dailies so if crew members  see it, they may take you up on it.> I'm sure you will be very busy here but if you happen to have some spare time and desire a good meal...  You guys do a great job and deserve to be rewarded as often as possible by the people who use your site every day!  Especially after reading a recent e-mail from a not very pleasant person who didn't like the help he received.  What a jerk! <Happens - cannot please 100% of people 100% of the time.> Complaining about a free service that does everything above and beyond.  I dare that reader to find a pay service / store / person that can do any better.
Thanks for everything.
Rich
<Cheers, J -- >
 

- Strange Pump Noise - Guys, I have a slight problem with a new Panworld 100PX-X pump that is hooked into my closed loop.  The pump has a 1" inlet and 1" outlet... but I'm running 1 1/2" hose down to the pump to make sure it doesn't cavitate.  I have a 1" hose coming out of the pump up to my closed loop manifold.  I assure you the pump is completely isolated from vibration type noise.  I have attached a picture to show you my setup. My problem is that there is a slight intermittent spitting sound coming from the impeller portion of the pump. <Sounds like you're drawing air every so often.> It never really stops, but it's a random noise (not cyclic).  I'm sure its not cavitation, because there are no bubbles going down into pump inlet (I can see through the clear hose). <They wouldn't have to be very large.> The pump has plenty of water to work with.  Premium Aquatics told me to take apart the pump and inspect it for something inside it... but I'm only running freshwater for my test setup... no sand, coral, etc.  I took it apart and found nothing out of the ordinary.  After assembling it and running it again... the same spitting sound was there.    Moving the pump around does not affect the noise. <Would suggest you use the valve on the output side to throttle the pump back ever so slightly and see if this noise still occurs.> Any idea what it might be? <Beyond air in the line, no.> Have you ran into this issue before? <Not on my own systems.> (By the way, I'm out of the 30 day internet warranty period... and I'm just curious to what could be causing this because I think I've done everything right with the plumbing) Thanks, Cody <Cheers, J -- >
- Follow-up on Strange Pump Noise - Follow up after some testing... After reading more WWM FAQ's, I stumbled on the fact that might pump might still be cavitating even though I have enough water for the pump?? <Can happen.> I don't understand this... <Air induction in the plumbing.> But I guess it is cavitation that I'm hearing even though there isn't any air to cause cavitation.  I have 1200 GPH running through my closed loop manifold to 4 evenly spaced LocLine nozzle outlets (300GPH each).  It works great along with my (2) 300GPH return nozzles for a 75 gal tank. What's strange is that I blocked one of the nozzles with my finger thus increasing the resistance to the pump and the spitting noise went away instantly.  Why would more resistance to the pump stop the cavitation noise?? <Supply versus demand.>  It seems like it would be just the opposite.  Along the same lines I closed off part of my pump outlet to the manifold using the ball valve.  After adjusting it to put more load on the pump, the spitting noise once again stopped.  Can you guys explain this madness?  I surely don't want to only have 3 closed loop manifold nozzles although I guess I could. <I'd just close the ball valve a little bit...> And I'm not sure its a good idea to restrict the pump outlet with the ball valve. <Will only up your electric bill a little bit - will not harm the pump.> I am confused here. <The pump is just driving the system more than it can actually take in water. This may seem counter intuitive because you increased the inlet side, but you just have to take my word for it that this is in fact possible. The increased diameter of plumbing right before the pump could be inducing turbulence at the restriction and this is what is causing the cavitation. Throttling back on the supply side is just reducing this turbulence.> Thanks, Cody <Cheers, J -- >
- Closed Loop Bubble Trouble? - Hello Good People, John Here; This is not a question but rather I was moved to provide input regarding a question from yesterday where the individual had pump noise/cavitation trouble on a closed-loop circulation system.  I myself have tried to get a closed loop system going using a MAG350 (as a test bed, since I had one) and later with a MAG950 to provide the desired circulation with my final plumbing. The plumbing consisted of a pipe going up and over the rim to the pump, through a SCWD and two lines back to the tank.  What I found, and what my limited knowledge of fluid dynamics suggests, is that if your pump draws water faster than it would flow by gravity, a low pressure is imparted on the water.  Since the solubility of gas in water is proportional to pressure, any dissolved gases in the water may come out of solution in the form of bubbles (akin to opening a bottle of soda pop) which will cause pump cavitation and, in my case, bubbles in the discharge. The solution is to throttle the pump discharge valve (reducing flow and tank turnover) or increase the diameter of the suction line (preferred). This idea was proven nicely with the MAG350 which performed well with a 1" suction line whereas it cavitated with 3/4 or 1/2" line. Alas, with the 950, a 1.5" suction line was required and the height of the elbow above the tank (un-drilled, sigh) causes a sufficient temporary pressure drop at the elbow to cause the air to come out of solution regardless.  So far, I haven't figured a way around this and am still using power heads.  Some kind of wide flat elbow or two smaller ones in parallel may work, but I haven't tried it yet. <Thanks for sharing.> JT <Cheers, J -- >

Closed loop and sump questions
Greeting & Salutations,
< Good morning. >
I just read a couple of articles Anthony has written about closed loop systems and water flow and would like to ask your opinion on a couple of items.< Go right ahead. >
a) If I use a an external canister filter e.g. Rena Filstar XP2 (I will also use it for chemical filtration) and "extend" the return outlet across the perimeter of the tank using elbows would I have effectively created a manifold closed loop system. < Yep, you would have.  The only downside I can see is that it will be quite weak.  You would be better with a large pump. >
b) After much deliberation I have decided to create a separate refugium which will have a gravity fed outlet into the sump. I have 2 options of getting water to the refugium a) have a small pump to feed it from the sump. b) Attach a Y piece to my hang on overflow box and a attach 2 flexible hoses, one the  sump and the other to the refugium. I am leaning towards option a due to flow rate. What is your preference? < Tough question.  First I would make sure they new refugium can handle a very large overflow.  If you "T" off your return line it is possible a lot of the water flow will go to the refugium. Okay as for the two options, they both seem fine to me.  I would probably prefer to not add another pump in the refugium system.  I would rather T off the return line.  If you do add a pump I would add another pump in the sump to the main tank. >
c) One of my wet dry filters will be converted into a sump for my tank. Will I get extra denitrification capabilities if I place some live rock in the bio chamber area? < Absolutely.  This is a very good idea. > Can I grow macro-algae without a substrate - creating a second mini refugium (I know I can get algae on the rocks) < Without substrate?  Well with some Chaetomorpha you may be able to, but substrate would certainly help. >
d) Do you know when Anthony & Bob's new book will be out and where I can order it?
< I do not know.  I'm thinking October and I'll bet Amazon will have it. >
e) I plan to incorporate an auto top-off system. Should my reservoir be filled with RO/DI water or saltwater? < RO/DI water!!! >
f) I looked through the FAQs and even though there is much on addressing noise issues I could not find any advice for softening the noise in the sump after the a wet dry filter has been converted into a sump/refugium and the drip plate has been removed - I still would like use the filter covers. Any advice on this or please point me to the right link. < Hmmmm, not sure.  If you can extend your return line all the way down into the sump water (so it doesn't splash down) you shouldn't have any noise problems. >
Finally, I have spent a lot of time reading the FAQs and it seems that - especially in regards to a FOWLR- weekly cleaning/maintenance, weekly water changes and patience e.g. using quarantine tanks, proper acclimation/cycling/curing etc. can get me around using most water additives/supplements and commercial substrates and avoid most of the issues being discussed. I believe in the KISS (Keep It Simple Stupid) methodology. Now, I know reef systems are a different animal- or  am I simply missing the boat i.e. the complexity of this wonderful hobby (and expense)?
<To me, a reef tank is much easier to keep and far less trouble than a FOWLR tank.  The filtration issues and stress to the fish are just not as important in my opinion.  So I don't think I would ever set up another FOWLR tank. >
Thanks with much admiration < Good luck. >
<  Blundell  >

Closed loop and Return Manifold
Good day,
<And to you>
I have spend the last 2 days reading through your articles and FAQs on return manifolds and closed loops and I'm a little overwhelmed by all the information available. English is not my first language and some of the terms is a little hard for me to comprehend, so I was hoping you would be willing to assist me with something that you have probably assisted many many other people already.
<I will try>
I'm in the process of planning my new reef tank of approximately 150 gallons and would like to design a closed loop manifold for water movement/circulation. The tank is not built yet, so I can decide now how many holes to drill and where. I'm having difficulties understanding the design of the inlet to the closed loop. If I understand correctly, I can either use an "over the side" pipe into the tank or a drilled holed in the tank for this. In both cases the pump will 'suck' water from the tank via the inlet and pump it back via the return manifold (correct ?).
<Yes, correct>
In both cases I need to use a 'strainer', which is almost like a little filter on the end of the inlet to prevent the pump from sucking in fish. Which one of these two methods would you prefer ?
<Either will work>
If I understand the drilled method correctly, this is simply a hole 2-4inches below the water surface that is connected to a pvc pipe on the outside, which immediately turns 90 degrees downward to go to the pump below (is this what they call a bulkhead?).
<One name, yes... also known as a through-hull fitting, gas jacket fitting...>
Is one advantage with the drilled method perhaps that the pump does not have to be primed ?
<Yes>
If you don't mind, there is one last question - my return pump for the closed loop will probably be at ground level, which means it will have to pump the water upwards around 5-6feet, which means that even if I have a pump that can do 3000Gallons/Hour, it will probably only do about half of that or something, so I probably need to have two of the closed loops installed if I want to turn the water over 20times, one for each side of the tank?
<Actually, with the lines filled, there is little head pressure loss>
I feel really guilty sending you these questions, because I can just imagine how many questions like this you have to deal with on a daily basis, but at the moment I feel that my head is going to explode after 10 hours of reading FAQs. Words like 'bulkhead' is not the kind of thing I'm exposed to here in South Africa very often :-)
<No worries... A friend who has lived with us a dozen years is from Swaziland... I grew up in the Philippines and Japan... lots of cross-cultural experience>
Thanks in advance
Chris
<Welcome my jabulani. Bob Fenner>  

Pump Sizing/Plumbing For A Teed Manifold - 05/21/05
Hello,
<Hello Frank>
I have a 135 gallon reef tank, currently running a Gen-X 1190 GPH return, and I have two 1-inch drains in the lower back of the system feeding into the sump.
<Couple thoughts/opinions here Frank.  First - Be careful not to overestimate what your drains can handle and plan accordingly.  Many claim 600 gph for a 1" drain, and under ideal circumstances it will probably handle it (albeit noisily), but I've found that a "safe" flow rate for this size drain is about half of what's usually recommended.  Be aware that flow will eventually start to restrict due to growth of algae and cryptic organisms within the opening/drain pipe.  Second - You mention the drains are installed in the "lower" back.  Unless you have some type of riser pipe/overflow box installed, your tank will drain to this point when the pump is off.>
My question has multiple parts: 1) Is my Gen-X giving a sufficient rate of turnover to my tank in general, and is it powerful enough to give decent flow to a teed manifold with six or so outlets, enough that I can forget about power heads?
<On its own, no, even before accounting for head loss.  Some suggest a minimum of 10x total tank volume for flow, I feel more is better...20x plus.  When figuring number/size of outlets for the manifold figure 400+ gph for each 1/2" outlet and 800+ gph for each 3/4" outlet on the manifold.  Its my opinion your current pump would limit you to two 1/2" outlets on the manifold.  With a proper pump/manifold design (much covered in the FAQs), yes, you will be able to forgo power heads.>
2) If not, what should I upgrade to and will this require   additional holes cut in the tank for drainage?
<Assuming six 1/2" outlets, you're looking at a pump in the 3000 gph range before head loss.  As for your drainage holes, I would plumb the two 1" drains directly to the pump and create a "closed-loop with the manifold.  You really don't want to try to push this volume of water through your sump.  Add another 1" drain and plumb the MAG 5 for your sump return.>
3) I am running a 500 GPH Mag 5 (and plan to add a second Mag 5) inside the tank at the moment.  Between this and the return pump am I giving respectable (I know it is not ideal) water turnover for the size of my system?
<Could be made to work, though the manifold is a much better idea.  Be sure to adjust all flow output to interact in a random turbulent fashion.>
Lastly, I know the answer to this could potentially fit under multiple categories on your website, could  you please post it under Plumbing 18 FAQ so I can find it easily.
<I don't make the actual postings on the site, but be aware you get a reply returned directly back to you as well.>
Much Appreciated, Frank Janes
<Regards, Eric Russell>

Manifold
I'm wanting to put a manifold on my 55 gallon glass aquarium, I ordered a Sen 900ga
specs can be found at www.wonbrothers.com, then selecting pumps, Sen 900ga.
The question I would like answered, is would it be wise to tee off the pump sitting inline on shelf behind tank plugged in UPS, one being to the manifold with 2 outlets on back with 2 on front directed at same location, 1 centered on each short side.   And the other to the Remora Pro skimmer I already have with the Mag 3 pump.  I ask this since Aqua C has remarked that a Sen 7 pump could be used for even more efficiency.   The Sen 900 seems like it would have enough water flow to run the manifold at 10+ times gallons of tank to the manifold alone, and the skimmer without a problem.  
<I am not a fan of such valving... would run the skimmer on its own pump>
There is 60 lbs live rock, about 5" -6" of sand.  Also have a penguin 350 and Fluval 204 with uv light on its output,  that may go to a 30 gallon  QT tank.
Also would like to know, what size pvc to put around the rim and which size outlets that I should use.  I'm guessing 3/4" pipe around with 1/2" outlets.
<Likely would go with just half inch all the way around... no more than the discharge side/volute of your pump... and ideally have all plastic valves or other simple means (drilled slip plugs) to restrict the discharge points/outlets in the tank... push these in so they can be wiggled out (likely with pliers) should you like to change them>
I was looking for the Sen 700, but the 900 is only $10 more.  What a bargain if it is dependable.
<You'll soon know>
Another reason, I ask this, is pumps in the tank don't exactly look like something that would be in the environment we're trying to simulate.  As well as removing a heat source.  I have heaters for that, and really don't want to have to purchase a chiller.
Also, I'd love to get a Pearly or Bluespot Jawfish, and lawnmower blenny.  
Currently, I have 2 Ocellaris clown, 1 lipstick tang?,
<A Naso lituratus? This tank is too small for this species>
1 firefish goby, 1 green chromis (timid), 1 mild mannered yellow tail damsel (returned aggressive 1), 1 Singapore Angel.   If I put the Jawfish, I'll get a bag of crushed coral and put in one end of tank or scattered about?  I suppose with this fish, I'd have to leave an area without much rockscape for an
"open" area of tank and make sure top has NO openings.
<Mmm, keep reading, scheming... you'll do fine. Bob Fenner>

Loop Manifold questions 4/21/04
You really do burn the midnight oil! 
<At times like now (post and pre-travel)... yes, very much so <G>>
Thanks for your dedication and suggestions! I have a couple of follow-up's. This tank will start off as FOWLR, but since I'm constructing it, I want to plan for eventually going reef with it. If I dedicate a pump to the closed loop, then I wouldn't need to go with 3 2" upper back wall bulkheads as these were intended to provide enough drainage for high turnover through the sump to display. In other words, would you simply put a pump behind the back wall display (below intended water level) with one bulkhead for input and then connect to the perimeter loop? 
<Yes... this works best for most folks and is exactly what I am doing for the next/latest personal display tank of my own being set up>
If I only have one input to loop pump, fully submerged bulkhead, what would be the impact on noise level, or
would you recommend the loop suction side of bulkhead not be fully
submerged for maximum silence?
<Hmm... I'm really not sure what you are asking, mate? If the pump draw is flooded (below the water line and gravity overflowed)... then the noise of the closed loop with effluents at or slightly under the water surface will be minimal - relatively speaking>
Would you still recommend a sump?
<Yes... they are quite convenient for so many reasons>
What sump to display turnover is recommended? 
<Slow is OK here to minimize salt creep, noise, etc: 5-10 X would be fine>
Any recommendations on a dedicated loop pump (which in this scenario would have close to 0 head)?
<Iwaki (Japanese made) is still my first choice... then Sequence pumps are my second choice presently. kindly, Anthony> 

Closed Loop Manifold...
Good morning! 
My husband and I are preparing to set up this closed loop manifold (maybe just one pipe in back across the whole back) in our 90 gallon acrylic. We checked with LFS man who had the tank made for us. He said that all drilled holes and bulkheads can handle the new GPH; we just have to change what he called the spur fitting. We are considering either the Pondmaster¹s Mag Drive 18 or 24. With one, considering the overhead, it will actually be about 1200 GPH and the other, 1800 GPH. 
So 10 x's or 20 x's the turnover... hmmmm..? Questions are: 
1. Anthony states in his article that 6 tees for return water is max for 100 gallon tank. Could I have more?
<Yes... of course, any given flow rate, pressure will be diminished per outlet in terms of outflow with increasing number>
2. My husband talked about using a smaller PVC pipe to "pinch" the water to increase flow. Much like a plumbed house. Main line coming in is bigger and then goes to smaller to increase the pressure. Is this o.k.?
<Yes... a good idea>
3. And basically, how do you make sure you are utilizing the max GPH and not causing back pressure because you used too few holes? How do you make sure you don¹t have too many holes thereby making the pressure too gentle coming out and thereby losing effectiveness of the reason for manifold?
<Mmm, can be done mathematically or by assay (actual practice)... my advice is to go the latter route... Not gluing/solventing pipe, fittings on the inside of the tank... looking at the resultant flow with the pump on, tank filled about all the way... experimenting with changing out diameter, number of fittings... until you have about what you want, what you're going to get... taking all back out, apart, drying, gluing together...>
The rest of the information provided seems easy enough. These are my only questions....except, as you answer them I'll probably find more! Ha.
Thanks.
From MI
<Welcome. Bob Fenner>

Closed Loop Manifold 4/14/05
Anthony, I'm planning to build an aquarium out of glass 72"L x 30"Wx 24"H 1/2" glass. I have planned to use 3 2" bulkheads (top back wall of tank) draining to a sump. I plan to use a Sequence Hammerhead for the return pump (approx head 18ft). Sequence suggested 2" piping off the return (in order to maximize flow vs. pressure)...
<Yes... understood>
...which means I would have to go from 1.5" (discharge) to 2" up to the tank at which point I wanted to do a closed loop around perimeter of tank. 
<Good>
I have been told that the water level should not be over the 2" bulkheads. In other words maybe half up the bulkhead to reduce noise. 
<Quite correct! For safe running/operation, do not overdrive the drains to the point where their running level is half of their capacity or greater (too noisy if nothing else)>
My problem and hence questions have to do with how to configure the piping. 
<The Closed loop pump in this case should be on its own drilled loop, and not tied into the sump>
I have to put bracing all the way around the interior top of tank, but also take into account room to place the 2" pipe going around the perimeter (which will reduce to 3/4" for outlets), and try to keep the bulkheads slightly above the intended water level (otherwise the loop will run into the bulkhead baskets or bracing or.....), and also consider how to put a glass cover (lid/lids) over this whole set up. What suggestions, concerns, changes, etc might you suggest to make this work? 
<From what little information is provided, I see no problems>
Also, any suggestions on where to obtain black silicon for putting together an aquarium? 
<Google until you can't Google no more <G>. And the big mail order companies perhaps like MarineDepot.com, CustomAquatic.com, ThatFishPlace.com, etc.>
Many thanks, you guys are the best!
<Kindly, Anthony>

- About Closed Loops -
Would like to ask about closed loop. 
<Ok.>
I have 70x24x23 inch tank and would like to do a closed loop. I have bought the pump (Senso), which is about 7500 liters per hour, would like to know that it is too strong for the closed loop. I have seen one pic from http://www.wetwebmedia.com/pbfaq12mar.htm - should I do it the same way? 
<With some caveats - you need to make sure you have valves on the input and return sides of the pump. I'm assuming you don't have bulkheads in your tank for the closed loop, which means you'd use an up-and-over type of feed and return lines, which will both create a siphon which would need to be shut off if you decide to clean or service the pump.>
The return pump is 3500 LPH. Is it affect the closed loop? 
<Should be fine.>
Thank you very much,
Bing
<Cheers, J -- > 

Water flow options: manifolds 3/16/05
Dear Anthony
<Cheers, mate>
I read with interest your article on flow in a reef tank. I, like most aquarists with an advanced set-up have more than my fair share of Maxi jet powerheads in the tank. I have however got a very large Eheim 1080 with a return overflow box servicing most of the flow within the tank so flow is quite turbulent (on the return side of the tank). I do however have dead spots which I have removed (not very successfully) with the use of an array of powerheads.
<Indeed... that's a challenging way to go about it>
Do you know of a method of attaching LocLine modular hose to one of these buggers? If not then a pump that I can purchase here in the UK that I can sit in the sump and array with LocLine manifold and pipes? Would benefit from your suggestions here.
<I do believe the closed loop manifold with a single pump or two is best for the long term. Do read the thread of links stickied at the top of the All Things Salty forum at reefcentral.com. A couple dozen fab threads with pics>
PS Good article on flow by the way (anemone owners take heed).
Regards Jim
<Thanks kindly my friend :) Anthony> 

Closed Loop water circulation 3/16/05
I've been not able to see answer to a basic question about closed loop schedule.
<do see the extensive list of links I have to this subject over in the "All Things Salty" forum at reefcentral.com. There is a sticky thread at the top of that forum... many posts with pics :)>
My setup is a 180g reef + 75g sump. I setup a closed loop with two 1" intakes in the two overflow boxes to feed a Dolphin Ampmaster 3000.
The return is made in 9 different locations in the tank. The tank has been running for 3 months and my soft corals and fish are doing fine so far.
<ahh, good to hear>
I run the closed loop continuously - no stop. Do you think it is a good idea or do I have to produce some kind of intermittence? thanks, Didier
<random turbulence is very fine and arguably better. Leave it exactly as you have it. Wave timers are not needed. A waste of money IMO, although current switching devices (versus wave timers that shut off pumps intermittently) are novel. Anthony>

Sump and Closed Loop Manifold 3/2/05
Bob, I have read thru countless Q&A's on wetwebmedia.com, but still I can't figure out the best way to set up my new tank plumbing. Hopefully you can help. 
<Adam here today. Thanks for looking through the FAQ's first. I hope I can help!>
I have a standard 75 gal rectangular aquarium and I want to set up the closed loop manifold system (No powerheads!). My glass has not been drilled yet, so we have flexibility here. My tank is going to be a reef tank with soft corals, fish, and inverts, but I would also like to design for some future flexibility if I decide to add more advanced corals later on. I need some guidelines for my system setup....Please help!
1) What GPH range do I need going through the sump?
<If your sump is just a sump (no refugium or sand), then the range can be from zero to infinity. The limits are really determined by what your drains can handle.>
2) What GPH range do I need going through the closed loop manifold?
<For reef tanks, I generally recommend at least 10x the tank volume, so at least 750gph.>
3) What bulkheads overflow sizes would you suggest for me? I was thinking (2)-1.5"s for the sump and (1)- 2" for the closed loop. Or, would (1) 2" bulkhead work for the sump?
<The number and size of drains depends on the flow through your sump. A single 1.5" drain will handle about 750gph. For the closed loop, you want to make sure that you distribute the "suction" of the inlet widely enough not to suck up fishies! For a 750gph flow, a single 1.5" inlet with a large strainer should be sufficient.>
4) I still haven't found a site that tells me the max GPH for the range of bulkheads...can you help a little more with that? <We get that question so much, I may go make a WWM page! For drains, I would guess about 300,750,1000 gph for 1", 1.5" ,2"  bulkheads. I would make a similar suggestion for closed loops as long as a large strainer is applied.>
5) How many outlets do you recommend for the closed loop? Is 3-4 enough?
<At 1/2" each, that is probably too many unless you provide more flow. If you use too many, the flow will be too slow to be effective.>
6) What GPH range per closed loop manifold outlet do you generally shoot for?
<This again depends on the size. For 1/2" outlets, I would try to get about 300gph each.>
Thanks in advance for your help. -Cody
<Best Regards! Adam>

Re: New 75G tank setup: Sump and Closed Loop Manifold
<Don't know where Adam's gone off to, so am responding>
Thank you for your quick answers to my setup questions. After reading through your answers, I now have a few more questions about the same setup (75Gal): My local reef guy can drill holes up to 1.5" bulkheads. 
So I plan to use 2 holes for the overflow (sump) and 1 hole for the closed loop manifold (all holes being 1.5" bulkheads).
<Okay... the return does not have to be this big... just the size of the plumbing/fitting from the pump discharge... likely no more than 1" diameter>
1) If I do include a refugium in my sump, then what should my GPH (in the sump) be and why would it be different than not having a refugium?
<Good question... how to state this... it's actually better to have the flow here "running in parallel" rather than series... that is, to have a much slower (a few, like a handful) turnovers per hour in the refugium itself>
2) If I try for 750 GPH through my closed loop manifold, and each one 1/2 inch outlet should have about 300GPH, then I am basically only going to have 2 outlets (returns) in my closed loop manifold (375 GPH per outlet)...is that correct?
<Mmm, the math looks about right... but I would make more discharge points here>
3) If so, then would it just be better to split the flow with piping instead of plumbing a closed loop manifold?
<If all you were hoping to do is discharge the water from two points, yes>
4) Assuming I have 750GPH in my sump and have 750GPH through my closed loop...both will be split into 2 returns each for a total of 4. Is 4 returns of 375GPH each enough to cause a sufficient turbulence in my 75G tank without the use of any power heads? (assuming I use modular piping and nozzles to accelerate the flow)
<Yes>
5) Any other corrections / or comments about my suggested setup would be appreciated.
6) I have read in other Q&A's that you only want to run overflows at half their possible flow rate to cut down on noise. Is this true?
<Mmm, practically speaking this is not a real concern... as you will find>
7) I assume since there will be no air introduced in a closed loop, I would probably be able to max out the flow through the bulkhead, and not use the "half" rule talked about in question #6...Is that correct?
<Yes>
8) What are the best all-around pumps (brand) in your opinion that combine reasonable cost, low noise, and reliability? (please consider my proposed setup in pump selection)
<Please read here: http://www.wetwebmedia.com/pumpselmar.htm and the linked files above... You will find there is some sort of consensus re manufacturers, the rationale for such... Bob Fenner>

Refugium, Sump, Closed Loop, and Overall Tank Flow
With your generous help, I've been planning my new 75gal rectangular reef with a regular 31" tall stand; however, when considering adding a Caulerpa refugium, I have ran into a bit of a snag. My plan was as follows: To get 20x of overall flow without the use of powerheads. I planned to use (2) 1.5" bulkheads as drains for the sump and pump this 10x (750GPH) of return up over the top of the glass and into the system. A separate 1.5" bulkhead was going to be used as an inlet for a closed loop which also went over the top of the tank and in for another 10x (750GPH)---4 return nozzles total. (Bob agreed that this was a good setup).
<Still do>
But now I am considering putting a refugium in my sump and possibly grow Caulerpa. The max flow rate that you suggest for the sump/refugium is only 2-4x instead of 10x (that's a big loss in flow!) Bob also suggested that running the sump and refugium in parallel was a better way to go.  
<Is... or possibly adding another sump/refugium altogether>
I was set on running an all in one refugium/sump like the picture shown in Get Thee To a Refugium, but if I do that, now I've lost 6-8x of flow which I must make up for somewhere else. It seems like I need 2 separate sumps one with a refugium and one without which means I need yet another pump I guess.
<Possibly... or a plumbing manifold... with valving... and one pump>
The problem is that I don't have room in my stand for two of them to run in parallel nor have I found any sump designs that show parallel flow like you suggest.
<Could one (sump) be run above the main tank? Outside of the stand area period? Doesn't need to be just put under...>
1) What are my options to have a single sump/refugium but not limit my flow down to 2-4x?
2) Are there any links that would help me design such a parallel flow system in such a limited space?
<Maybe Ozreef.org...>
3) I guess if I was only running 2-4x through my sump/refugium, I would only need (1) of the 1.5" bulkhead drains (running half max flow) and I could use the other (2) 1.5" bulkheads to feed 2 closed loops?
<Could... but one loop would be fine...>
4) Is there anything wrong about running a sump refugium at 10x ?
Thanks in advance.
-Cody
<The contents might well get swirled about like being in a Maytag! Bob Fenner>
other dialogue provided below for reference
<Thank you for this.>

Re: Refugium, Sump, Closed Loop, and Overall Tank Flow
Bob, Can you explain this further? I'm not sure I understood what you meant. A plumbing manifold in the sump? What does this look like?
<Possibly... or a plumbing manifold... with valving... and one pump> 
<<Like a "gang valve" for air distribution... you can "tee" off the discharge from the one pump... and use two valves to regulate water flow>>
And by the way, I cannot put a refugium on top of my tank.. Everything  has to be within the cabinet below.
<<Okay. BobF>> 

Closed loop manifold
I have a pump that runs 1900 gallons @ zero head and shuts off at 45. This pump will be in the basement and will have about 20 feet of head by the time it goes through the manifold at the top of the tank. Champion lighting said I will still have about 1200 gallons per hour. I am running another closed loop pump same size as the sump to a manifold at the top of the tank as well. My question is do I need to run 2 separate manifolds or can I hook both pumps to the same manifold and save some clutter at the top of the tank? 
<You can do this providing the plumbing is sufficient enough to handle the volume of water. Personally, I don't like hooking up two pumps to one outlet. I think it lowers the efficiency of system. James (Salty Dog)> 
Thank you. 
<You're welcome> 

- Plumbing a Return Manifold -
Hello and thank you for all previous advice.  I am in the process of creating a return manifold like the one Mr. Calfo has posted.  I am planning on using a Blueline 200 with 1" inlet/outlet.  I plan on using 8 T's in the manifold and use adapters with swivel nozzles to finesse circulation. Question 1: Since pump outlet is 1" should the whole manifold be constructed with 1" pvc? <I'd plumb up to the tank in 1"... for the manifold perimeter around the tank, I'd use 3/4".> Question 2: I would rather support manifold above water line/above tank center brace and extend T's and nozzles below water surface for aesthetic reasons. Any issues with that? <Not that I can think of, provided you put a check valve in the main return line, before the manifold.> Question 3:  I don't want to drill the tank but would rather plumb inlet from display-over rim-down to pump.  Problem? <A huge one... would create a siphon.> If not, as I understand it, or maybe not, in case of power failure, since this a closed loop (no sump) method there is no chance of flooding, correct? <Didn't realize this was a closed loop, but still must make an allowance for a leak in the plumbing/pump. Siphons are big potential trouble.> Question 4:  Scenario--> power fails resulting in inlet plumbing over display rim drains back to display creating a air gap but there is still water in vertical pipe above pump.  Will this be enough water to prime the pump when the power should happen to come on again or will I burn up the pump trying possibly creating a fire and burning the whole house down b/c I didn't want to drill the tank??? Duh <Hmm... good question and something I would test once you have the whole thing built. Do think that if you use the check valve inline on the return, you should have enough water remaining in the plumbing to prime the pump. Again, would test this to be sure.>
Thank you for guidance and patience.
Avid reader
<Cheers, J -- >

Closed loop system
Hello,
I have a few questions regarding a 46g bowfront I'm in the process of setting up.  I don't have room for a sump, so I'm planning on using a hang on skimmer and an external pump set up in a closed loop system. << Good ideas. >>  I'm considering drilling the back of the tank for drain and return lines to minimize equipment going over the back. << Great idea. >> For the return, I thing I'm going to use two 3/4" lines coming from a SCWD.  My question is about the drain.
What would you recommend for the bulkhead size. << One and a half inch. >> I'm thinking that about
600gph(at 4 feet) should be about right for this size tank.  Any pump
recommendations for this setup would be greatly appreciated as well. << More important is to make sure you use ball valves and unions, you will have to take the pump out for cleaning, so plan ahead. >> As
always, cost is a factor.  Thanks so much for the great site.
<<  Blundell  >>

Plumbing, marine, closed loop
Hi Guys....wonderful site. Many thanks
>>Thanks back!<<
A quick question if I may?  I have a 75g display, 30 g sump/refugium. Plumbing is a 1" bulkhead (I.D.) drilled at the back in the tank with a flexible hose going into the sump with a mag Drive 9.5 forcing the water back up over the rim of the tank into a single elbow/effluent. A lot of flow/velocity...too much laminar I'm afraid.  But So far....the balancing act is perfect. Water level in sump matches the pumps output pretty nicely as there is no need to use the ball valve to divert flow. (this seems to defy the 600 gph flow rate I read about with a 1" bulkhead) I have been reading Anthony's suggestion about making a return manifold to more evenly disperse the water throughout the tank. Probably will give that a go this weekend.
>>Great. Such a manifold works out very nicely.<<
  Also, I have 2 small Rio's in the tank for additional flow,(240 gph each)  along with a Euroreef CS-6 skimmer in the sump stirring things up even further. Will this be adequate flowage for my setup? I do not have any livestock in the tank yet...just 130 lbs of Fiji rock.
After scouring your site...I've seen that 20x tank volume is pretty much the norm these days. I do want a few fish...but mainly corals and inverts.
>>You don't really need 20x moving through the sump. More flow in the main tank is nice though.
>>The Rio's make me a little nervous though, they have a rep for burning/shorting out<<
I was wondering if adding a closed loop system would help? Or, is this overkill/un-necessary?
>>If you want more flow, sure! Sadly, the amount of flow in a tank is partly a function of the corals you keep and personal preference. I know on my tank, I never seem to have enough flow regardless of all the extra closed loops I add!<<
I do not want to drill additional holes for plumbing, so I was thinking about looping pvc from the top of the display tank, gravity feeding into another mag-drive of some sort, (size recommendation would be helpful) then shoot right back up into the display (no even going into the sump...just independent) maybe splitting the effluent  into 2 feeds?  ("T") this way...could I eliminate the Rio's inside the tank?
>>Sounds good to me. I like removing any kind of power head from the tank, and I run my closed loops over the top instead of drilling - I think it give greater flexibility for the future. You can also look into a device called a SCWD that is basically a 'T' that alternates the current between both sides of the 'T' by a series of gears powered by the water flow. There are, or course, more expensive options like the oceans motions 'Squirt' - I just got one to replace two SCWD's and I love it so far! As for pump size, that depends on how much flow you want. Mag 9.5's seem to be a good all around size. <<
Thanks so much for the insight...
>>Hope it helps!<<
Mike Gaydos
>>Rich<<

Re: Plumbing, marine, closed loop
Hi Rich, Thanks again for taking the time to respond to me. All this information is surely a lot to digest for a newbie like myself, but I keep reading and learning. Anyway, I guess my main misunderstanding about flow rates comes into play when the term "turnover" is used. I thought 20x tank volume meant all water must go thru the sump. So then what you are telling me is not all of that 20x must go thru the sump but rather just get "moved around" by a combination of sump, skimmer, powerheads in display, and closed loops??
>>That is exactly what I am telling you! Its important that there is 'enough' flow around the corals, not that all the water  must pass through the sump>>
Could you please tell me what the desirable amount of water MUST move thru the sump/skimmer to be effective at filtration and the rest just for water movement?
>>I can give you a sideways answer - as much as possible.
        In my case, 600 gph moving thru overflow/ return, 350 gph thru skimmer, and possibly another 600 gph moving thru a closed loop over the top of the tank be adequate? Sure seems like a lot to me....
>>The skimmer doesn't count as flow or turnover unless it is a HOB skimmer. The animals in the tank could take more flow, but you don't have to add more unless they need it. Does it move around the tank briskly? Are there no dead spots? Then you are fine! >>
     One other question please about closed loops. How do you prime the pump if it is fed by the line hung over the top of the tank?
>>The easy way is to fill the line of the loop with water before you hang it over the top of the tank. You can also plumb in an ball valve above the tank so you can open it and fill the line with water. That makes sense, really>>
I'm sure the supply
must at least originate roughly in the middle of the tank with some sort of filter/screen over it as not to suck in anything undesirable?
>>Screen yes. You can put the intake where ever you like in the tank (I hide mine behind the rockwork) or if your overflow will take the extra flow, you can stick it in the overflow.>>
Once it is
primed...it should continue on until power is disrupted or would it continue to siphon?
>>Yep!
(ok...that was 2 questions)
>>3!>>
Oh....one more....please......where does one drill the anti-siphon hole in the manifold as described by Anthony?  Cant have it above the water or it will spray while running....so in the "loop" somewhere pointed downward or is it even necessary at all?
>>Some people don't use them, but they are a good idea. If the power goes out, the manifold will continue to siphon your tank. The anti siphon hole does go slightly above the water line, drilled in such a way as to point slightly downwards so its 'spray' doesn't hurt anything.>>
Thanks so much....really!
Sincerely
Mike Gaydos  (rookie)
>>My pleasure!>>