Questions about building overflows and drilling a tank?

[Palster]

That explains the confusion. I was thinking of the of the siphon style overflow boxes. Those are the ones that I believe can cause flooding for the reason I had mentioned in my last post. I had never considered notching the glass and building the overflow on the outside.

Glenn

[Richy44]

[SuperFudge]

Hello,

The total length would be your length of the overflow x1 and your depth x2.

so an 8x5 oveflow would be 18" of actual surface skimming.

But i couldnt say it would be 5" in depth because i was unsure of bracing (cleats and or euro) in your tank...the 8" is a minimum width to fit a 2 1/2" hole(1.5"bulkhead) and a 1 3/4" hole(1" bulkhead) aswell as the street 1.5" 90 that you will use on your durso, aswell as typical flange size.

You/glass company must notch the top, rather than drill holes here, holes will not work.

Marc.

[Palster]

Thanks Marc for all of the information. According to Reef Central's Drain Size Calculator an 18 inch overflow will handle up to 1200 gph which should be enough flow if I decide to make the tank a reef tank later on.