OK ... this is the third overflow I've built, second I've actually constructed... learning a tad more every time, by the 10th or 11th overflow I think I'll have it down
my objective is to have an overflow that fits behind my tank, which is close to a wall, not leaving a lot of "width" available for a large drain box (found on most commerical overflows)
so I designed an overflow that is 12" long by 3" wide. It has two 3/4" drains and a 1.25" (or maybe two 1") siphon. my target GPH
is ~400-500, not sure if two 3/4" will push that or not, especially since I'm using hose and not pipe. failing that, I should have enough room to ream out the holes for 1" drains.
so, here's so pics (more to come, ran out of good light)