Internal Overflow Question

[sidog1]

I'm trying to design an overflow for a 120 gallon acrylic tank. It will be eurobraced w/ center overflow. However, I'm trying to figure out the overflow. I'm thinking two 1 inch drains with two 3/4 inch returns. I'm not planning to push much flow through it, 600-800 gph. How are internal returns designed? Can I have holes on each side panel of the middle overflow drilled with a hole about 20 inches high for a locline return? In case of a blackout, would check valves prevent a flood from the returns? Any insight would be greatly appreciated. Thanks.

 

[dswong01]

http://reefcentral.com/calc/drain.php for drain size gravity feed. You can alway add ball valves at drain to balance the returns flows . Add a pin hole in return feed line inside tank to break siphon in case of power outage.

 

[sidog1]

thanks dudley, err i think dswong is dudley. i will incorporate the pin hole idea. maybe i'll just do 1 return since i'll only be using a mag 9.5 or eheim 1262...

 

[UCanDoIt]

One return should be enough and since you are using loc-lines, you can always split the direction of the flow with a Y. The pinhole idea works great, I have them on all my tanks.