Here we go! 336 gal acrylic tank with CL-Suggestions Plse

[LCATTIN]

Things are starting to slowly come together. I have a 336 gallon acryllic tank measuring 72"x36"x30"deep. 10" wide overflows in the rear corners. I am planning on a plenum/DSB to bring the bottom up 5" or so to make it easier to reach the bottom of the tank. Now for the CL system. I have read many of the past threads on CL through the back, over the top etc. and am still not sure what is best for me. I will be using a Dolphin AMP Master 7500 pump. Should be lots of flow. One of the problems with over the top manifold that I can see is working around the overflows in the corners. I figure I am going to need about 15 - 3/4" inputs to the tank to keep the flow to around 500GPH per nozzle. That's a lot of holes in the back. Also are 2 - 1 1/2" drains to the pump sufficient to keep suction down? As far as the back is concerned I have basically 4' wide by 24" high area to work in. Of course the top bracing is there and already has 4 holes drilled in it for Sea Swirls (I assume) I can take pictures if anyone would like to see it.

The main issue right now is cost as work is not real good right now so needs to be effective but cost efficient so we can forget the motorized ball valve for now.

What do you think?

Les - in Kokomo

 

[Meche]

Nice tank, I'm jealous and wish I had your problem. :lol:

You can get the same flow with (8) 1" holes or (5-6) 1.25" holes. You could then split the flow inside the tank using something like line-loc Ys.

 

[Krish]

Sounds like a fun project! Seeing the tank is acrylic, most people would say to drill...Much cleaner and neater than an over the top closed loop as well as you can have your outputs wherever you want. In all honesty, I don't think you'll need 15 outputs, but that is totally up to you. Here are a few threads that may help you some with a few ideas that you can browse through to get some output and plumbing ideas for closed loops.

http://www.reeffrontiers.com/forums/showthread.php?t=2062


http://www.reeffrontiers.com/forums/showthread.php?t=144


http://www.reeffrontiers.com/forums/showthread.php?t=14793

 

[LakeEd]

Krish has given you some great links! I also wouldn't think you would want 15 returns! 8 would be more than enough, especially if you planned on doing what Meche mentioned with using the 3/4" loc-line "Y" for dual output of each return.

 

[LCATTIN]

I'm still studying. Keep those ideas coming.

Thanks

 

[Krish]

Here's something that may help as well. These are photos of my old 38gal cube I did a closed loop on. I had (2) 1506 gph Quiet one pumps hooked up to 4 outputs so one pump ran the top left and bottom left outputs and the other pump ran the top right and bottom right outputs. You can get an idea of what the flow looks like coming out of the top outputs with "Y"s on them which was basically 750 gph shared between the 2 (about 375 gph each) and then on the bottom I just had a single nozzle on it which meant about 750gph was running through one nozzle.

 

[dnjan]

How about putting two closed-loop return bulkheads in the back, and then on the inside of the tank, immediately go into a true union from each return bulkhead. Then you can make a piece that connects between the two true unions (inside the tank), and add whatever plumbing (nozzles, etc) you want. If you don't like it, disconnect the two true unions and make something different.

Some reasons for this suggestion:

1) Bulkheads are expensive. Using just two, plus two true unions will save money.

2) Using two bulkheads allows your return from the pump to feed into a loop (you pump return will be split with a Y or a T to go into the two returns), which will keep your pressure for the various nozzles closer to even.

3) This way you can take the thing out if necessary for cleaning, changes, etc.

 

[Meche]

Using just two, plus two true unions will save money.

You won't want to run 7500GPH through only two bulkheads, unless they are very large. There would be too much pressure loss which would reduce flow.

 

[LCATTIN]

I am probably going to use 3/4" bulkheads. I just bought 4 on ebay for 15 bucks including shipping. I couldn't pass up that pump. Traded a dual MH retro for it plus it comes with the 8 way manifold and true unions. It should be just the right size for this tank.

What do you think about the size of the suction ports. The pump is a 2" so would 2 - 1 1/2's work or should I go with 2"?

 

[dnjan]

I would go with 2" for the input bulkheads. You want to minimize the velocity at your input strainers.

 

[Meche]

Either should work fine. I'm glad you picked up on the fact that area, rather than the diameter, is whats important.

 

[dnjan]

You won't want to run 7500GPH through only two bulkheads, unless they are very large. There would be too much pressure loss which would reduce flow.

Won't one 1-1/2" bulkhead have about the same headloss as four 3/4" bulkheads?

I thought headloss was approximately related to 1/(diameter-squared).

 

[Meche]

Head loss is determined by velocity, change in elevation, pipe length, and restrictions (elbows, tees, valves, etc.) Other factors are important but not to us, as reefers.
Basically the idea is to keep the velocity (or speed) of the water to a minimum. CL don't have to worry about the change in elevation, and pipe length and restrictions are optimized by efficient plumbing design.
(1) 1.5" pipe will flow the same amount of liquid as (4) .75" pipes at the same speed. This is because the cross-sectional areas are the same (A=pi*r^2). So in a way your right, although, I wouldn't think of a diameter having head loss.

Running 7500GPH through (2) .75" bulkheads is not a good idea because water velocity will be very high, and therefore very restrictive.

 

[Meche]

I would try to maintain the same cross-sectional area as the output on the pump. I found it to be 2" which equals 3.14 square inches. On the inlet side your fish might like (2) 1.5" a little better than (1) 2".

On the outlet side, if you run those .75" bulkheads, then you may want to order another set, use 8. Or you can use (4) 1". Or option 3, deal with the head loss and just use the (4) .75" bulkheads you have.

 

[LCATTIN]

Thanks for all the info as that is what I needed along with a little reassurance with what I am doing. I will have 6 -3/4 as I already have 2 here and I also have 4 1" in the house (2 of mine and 2 belong to a friend). Now to find some larger ones for suction.

Thanks again,
Les

 

[Meche]

Good luck. How about some pictures when you get it set up?

 

[LCATTIN]

That should be doable but it may still be a while. With the work situation I can only do a little at a time. I am still trying to scrounge some leftover wood from someone elses projects to build a stand and canopy. I have most all of the equipment and plenty of Kolorscape (Southdown) Sand ready to go.

 

[LCATTIN]

Here is another issue on this setup. I have a 70 gallon acrylic sump also. Right now it is drilled for a 1.5" bulkhead for a return pump. The overflows each have 1.5" Durso's installed. I think that these should do 1300 gallons each. Do you think I should just run 1 return pump or should I drill for the second one? I have the pumps. One is a GenX Mak4 and the other is an Iwaki at 1150 GPH. The Life Reef skimmer will probably set in the sump and I have a Red Sea Berlin also to add to it if needed. The sump is large enough to put both in there. I don't want to move too much water and decrease the skimming efficiency. Is 2000 GPH too much for a sump this size?

 

[Krish]

Do you think I should just run 1 return pump or should I drill for the second one? I have the pumps. One is a GenX Mak4 and the other is an Iwaki at 1150 GPH. The Life Reef skimmer will probably set in the sump and I have a Red Sea Berlin also to add to it if needed. The sump is large enough to put both in there. I don't want to move too much water and decrease the skimming efficiency. Is 2000 GPH too much for a sump this size?

Personally, I'd just stick to one. Less heat to worry about, less electricity and IMO not necessary unless you want a really high flow sump. I personally like slow flow through my sump to give the skimmer a good shot at in-coming water and not have it wizz right by. I make up for my flow with powerheads or closed loops in the tank and never really factor in my sump return as a primary source of flow for the tank as a lot of people tend to base a lot of their flow for the tank by the sump's return. Just a thought...Good luck on what you decide. By all means if you want to run both, there is nothing wrong with it. You just have to go with what works for you

 

[Meche]

OH Krish 2 more!!!