How big should my return pump be?

[Coraljunkie]

Hey folks I have a 125 gallon with fairly heavy bio load and 30 gallon wet/dry sump. So the question is how many GPH should my return pump be? I have a RIO 2500 on it now.. Oh and also I have a spare Lifeguard 2200 if needed. The head is about 4 feet. Thanks,Ken

Edited December 22, 2010 by Reefnewguy

[Derekreefer]

great question. Does anyone have a link to a calculator or is there a formula for calculating what pump you need?

[Eel Keeper]

You want something that is going to move all your water through it ten times in one hour at the hight it has to travel. For instance mine does 1200 gph, but once it goes up 4" it is reduced to 900 gph which is perfect for my 90 gallon. I belive the Rio does somewhere between 748 - 782 gph but would be reduced once it travels up a few feet. The Lifeguard 2200 pump does only 581 gph, so total you would only have 1363 gph at best. Still not quite enough IMO. I would look into getting one that is rated at 1250 at the height it returns into the tank.

[Toxiq Reef]

I aim for 4-5x

[Mike M.]

A quick search showed that at 4' of head loss, you are getting right at 500 gph of turnover with the Rio 2500 running as return by itself on your tank. If you follow Toxic Reef's advice, you are spot on with 5x turnover. Id Eel Keeper is your advisor, you would need to add a second pump or go with a larger pump. I think you are okay with 5x turnover personally. That's right where I have been running my display for right at a year now and it has worked just fine. In addition, higher turnover increases sump noise which I am not a fan of at all. So there you have it, depending on whose advice you follow, you either have the right equipment or need to buy a new pump!

Model Dimensions Outlet Watts Gal/Hour @ 115V. 60Hz

Max Lift in Ft. 0 ` 1` 2` 3` 4` 6` 8` 10` Rio 2500 5.1" x 2.7" x 3.7" 3/4" I.D. Hose

782 720 666 580 529 375 - - 10`

[Gonzobob]

I tend to keep in the 4-5x range myself. ReefCentral has a head flow calulator for many of the available pumps. You can use the calculator and plug in your pipe size and configuration to get a pretty good idea of your flow and a given head height.

[+Hydro]

As much as you can! I always go with a bigger pump and put an inline valve to throttle back the flow to exactly what you need. I turn it on with 100% flow and then turn it down until it gets quite enough and doesn't gurgle. The more the better though, just don't over flow the tank when you first start. I had a mag 9.5 that would overflow my 175 gallon tank in 10 seconds (at 100%) and the tank had (2) 1" overflows, if that helps you with sizing at all. I think that pump size should be paired with overflow size...not with the tank size. If its a 100 gallon or 200 gallon tank the pump size wouldn't matter if both are using 1" over flows, assuming that you wanted the most turnover possible.

[+lewk]

I run a Mag 18 on my 135.

[+Hydro]

Now that I think more about it the 9.5 was actually to small. I changed it out to a reeflo marlin and that is the pump that would overflow my tank so quickly. The 9.5 did seem fine for that tank until I started adding things to it like UV, phosphate reactor, refugium. Then I stepped up to the marlin.

[fishypets]

I personally like a slower flow through my sump which gives my skimmer more contact time. But in the main display let it rip I say! I'm running about 12,000 gph of flow in the display and only 500 or so through my sump. Tank size is roughly 200 gallons.