Return Size VS Overflow Size

[Tosh_Auer]

Im planning on getting my tank drilled for one overflow and one return and was wondering what size pipe to use for each of these? Ive noticed in other threads taht some people use a larger overflow then return and others who use both the same. What do you all do and if you could do it again what would you all do?

 

[mnreefman]

i personall would use both for the overflow and then run em through a spray bar as a return from the sump.... power it with a mag 12.5

 

[Tosh_Auer]

Ive already got a little giant pump for my return.
I am just wondering if the pump will push more water through the return then will come through the overflow.

 

[addict]

Normally you'd want a larger drain (overflow) than you'd want on the return. Water draining by gravity travels slower than water under pressure from a pump, so you have to make up for that by increasing the volume (diameter) of the drain pipe.
The best way to figure out what you need, is go to reefcentral's drain calculator (it's about halfway down the home page on the left), type in the gph you want capacity for, and see what it comes up with.
HTH.

P.S. As far as return size goes, you probably want to run at least 1".

 

[Brucey]

Tosh ..... I recently upgraded my return pump and immediatly started having problems with the drain. Make sure that the overflow is as big, if not bigger than the return (IMO).
I agree with RA ... at least 1".
Brucey

 

[nivek]

I have a bigger overflow than return.

 

[tankgirl]

Ditto. I've got 1 1/2" OF and 3/4" dual returns (run by dual Mag18s) on my 260.

 

[dwall174]

Tosh_Auer

Originally posted by Tosh_Auer
Ive already got a little giant pump for my return.

You’ll need to figure out what your head pressure on the pump will be, Then the amount of gallons per hour that you will be supplying to your tank. Here's some Plumbing Tips that should help you figure this out. Once you know the GPH that will be pumped into the tank then you can figure out the size for the overflow needed to allow it to drain out! Here's some gravity flow rates for std size PVC pipe.

1/2 " PVC
3.5 GPM
210 GPH

3/4" PVC
6 GPM
360 GPH

1" PVC
10 GPM
600 GPH

1 1/4" PVC
20 GPM
1,200 GPH

1 1/2" PVC
30 GPM
1,800 GPH

2" PVC
60 GPM
3,600 GPH

2 1/2" PVC
100 GPM
6,000 GPH

3" PVC
175 GPM
10,500 GPH