Overflow / Return Pump GPH ?

[kaiserg13]

Hey,
I have a 55g tank and im looking to build my own sump for it. After reading through this forum and other sites I think I have everything figured out, EXCEPT what flow rate I need to the sump and what pump will be needed to return the water to the tank.
I was looking at the cpr cs50 overflow which handles 300 gph. To me this does not seem like enough. I have about 60 lbs live rock with crushed coral (hopeully switching to ls soon) I also have a few corals and want them to have enough waterflow. The circulation in the tank now is coming from a fluval 304 and a aquaclear 70 powerhead, and the aqua c remora skimmer.
Should I go with a larger overflow like 600gph or is 300 enough?
And which return pump would be sufficient for each?
any help would be appreciated. Thanks! :needhelp: :help:

 

[bdhough]

Always good to go higher. 600 would turn your water over roughly 10 times an hour which is a good rate combined with power heads in tank.

 

[slock]

go with the 600 or +

 

[kaiserg13]

what return pump would work best with an overflow of 600gph. I know this depends on the height the pump has to pump upward and the number of 90 elbows etc. Does anyone have any recommendations?

 

[pontius]

similar question. what if you have 2 overflows for a total of 1200 gph? would one 700 gph sump pump be enough, or would there be a need for 2?

 

[kaiserg13]

Im new to this but i think if you have 1200 gph flowing to the sump and 700 gph back to the tank everything would work fine because when the h20 level in the tank dropped the siphon would stop until the return pump caught up. I guess it would be better though to have a return pump that was pumping h20 back to the tank that was closer to the overflow gph.
is this correct?

 

[at]

Thats a big difference, I was told the other day at the store 15-20 times flow. I have a 40 gallon and my pump is about 700gph. You should match the overflow to be a bit more then the pump.. not too much or else it will be shutting off (the overflow) fairly often. I guess its not a big deall. thats how its designed.. but might as well just have it flowing constantly.