DIY overflow

[kajunsausage]

I was going to make my own overflow and one question stumped me. How will I know the gph of my overflow?

 

[geoj]

If you google it you will find an overflow calculator.

 

[beaslbob]

IMHO if you're doing something like this overflow:
https://forums.saltwaterfish.com/vb/s...light=overflow
As long as the pvc pipe is 1"-1 1/4" you should be fine.
my .02

 

[beaslbob]

that is of course unless you have a huge tank. But for "normal" tanks ths should be fine.
my .02

 

[jackri]

Another part is the pump you are using -- the flow rate is usually determined by your pump as it pumps the main tank up the overflow should be able to handle that and drain back into your sump. A ball valve on your return line can help limit flow as well but actual flow rates are determined by the pump.
Now that being said your overlow should be easily able to handle what the pump can give out.