Overflow Sizing Question

[Teeb]

I'm going to be drilling my little prop tank to add a sump/better skimmer in a couple of weeks. I have some questions about the size of the overflow. I'm not trying to make it pretty and probably won't even use an overflow box. I'm drilling the back of the tank and using a street elbow. Return will be a Mag 3. Will 3/4" suffice or will 1" be needed. I'm looking at about 3' of head with an over the tank retrun, so I'm guessing about 250-275gph needing to be drained. Any thoughts?

[txg8gxp]

I would run a 1" bulkhead. I believe a plain 1" bulkhead is rated for around 300-350gph. More with durso/etc. plumbing above the bulkhead.

[txg8gxp]

http://www.wetwebmedia.com/BulkheadFloRateArt.htm

[Teeb]

Sweet, thanks Steve. 1" it is.