What size return pump for 90 gallon.

[jyach]

I am setting up an aga 90 gallon mega flow aquarium. Can you please tell me what size return pump i should use. I have a small sump and am concerned with micro bubbles in the sump and tank. I was thinking either a mag 9.5 or a mag 7. Or perhaps someone else has a suggestion? Thanks for your help in advance.

[scotmc]

Your looking for 600gph. I have a Ocean Runner 2500. Is a great match. You can do better than a Mag pump.

[sjm817]

Target 3 - 5x display size after headloss. 270 - 450 GPH for a 90G. If the sump is small, stay toward the low side.

[oct2274]

go no less then 600gph. i don't really like the mags because they are more noisy then some of the better pumps like the oceanrunner and eheims.

[crossi92]

Ocean Runner 2500.

[USC-fan]

I use a mag 5.

[sjm817]

A 600 GPH pump would be good to get in the 3 - 5x range after headloss. I prefer Eheims. A 1260 would work well, maybe throttle it back a little.

[rsw686]

I have an OceanRunner 3500 on my 90gal tank. With the head loss I find the pump is perfect. The stock AGA overflow handles the water flow without issue.

[sjm817]

Have you ever measured what the actual GPH is? You can put a 1G jug on the drain and see how long it takes to fill.

[xraydoc]

I also use the Oceanrunner 3500, but I divert some of the flow to my fuge via a T fitting and a ball valve. I think the size is good for my application.

[rsw686]

Originally posted by sjm817
Have you ever measured what the actual GPH is? You can put a 1G jug on the drain and see how long it takes to fill.

Nope I haven't measured the actual GPH. I would measure it, but everything is hard plumbed, which makes it hard to get a jug underneath the drain.

Using the head calculator it comes out to 675GPH.
(3.5ft vertical pipe, 0.5ft horizontal, 2 90 degree elbows, 1 ball valve, 1 union)

http://www.reefcentral.com/calc/hlc2.php

[sjm817]

That calc can be pretty far off IME. An AGA overflow is good for ~ 600 GPH, so I would want to be be below that.

[rsw686]

Originally posted by sjm817
That calc can be pretty far off IME. An AGA overflow is good for ~ 600 GPH, so I would want to be be below that.

Right. I'm just saying that is what I use and it works fine. The water is halfway up the overflow slots in the tank. Since the AGA can only drain 600GPH I must be right around that. If that is the case the OceanRunner 2500 would much lower.

I had debated between the two (2500 and 3500) when I bought the pump. I just figured that I could throttle it back a hair with a ball valve, or redirect it back into the sump.

[oct2274]

it is always better to go with an oversized pump vs one that just barely meets the needs. you can always valve down the output if needed or redirect extra flow else where. I person would go with an oceanrunner 3500 or eheim 1262 on that tank. Flow should be perfect after headloss and if you think it is to much just make sure when you plumb it in that you put a ball or gate valve after the output.

[sjm817]

I used a 1260 with my 90G and a 40G sump and thought it had great flow. It was ~ 425 GPH or so and was close to the 5x higher end of the 3 - 5x scale. A 1262 would have been way too much and would have needed to be valved back a lot. The OP has a "small" sump (what is small?). I wouldn't use more flow though it.

[rsw686]

My sump is a 20 gal long with two baffles in it.

[Garage1217]

I have a 20L sump I am building and also looking for a return... watching this thread