How to calculate what return pump I need

[AngeloM3]

I'm adding a sump/fuge under my tank. How do I calculate or figure out what pump (gph) I need? I know if I get one that does to much gph it will drain the sump.... if I get one that doesnt do many gph then the sump will overflow.

Please help

[doox00]

get one that about matches what your overflow will do, just make sure your return pump does not excede the overflow capacity and you will be fine.

[AngeloM3]

how do you calculate what my overflow will do? i have a corner overflow with a flex tube down to the sump

[mbbuna]

the first thing you need to know is how many gph your overflow and plumbing can handle. then how high the pump has to pump water.

when the pump is running only as much water that is being pumped is coming back to the sump(if the plumbing can handle it)

[mbbuna]

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

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

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

[AngeloM3]

thanks for the links

[sjm817]

Your overflow may handle much more flow than you need. The general rules is 3 - 5X display size. As an example, a 50G tank would be 150 - 250 GPH after headloss.

[AngeloM3]

yup..... i got a mag 5 now... thats going at 284gph after head loss

[sjm817]

Should be fine.

[AngeloM3]

yah.... its fine now... but i want to install a SCWD w/a Mag 12... but it wont be on a closed loop... so i gotta figure that out

[sjm817]

Figure the SCWD will cut the flow in 1/2. Mags are not good pumps to use with a SCWD. they do handle headloss (backpressure) well, and a SCWD adds a lot.