DIY Overflow

[vanimate]

Hi all. I'm ready to make my PVC overflow out of 1" PVC. My question is, how low does the lowest point of the overflow have to be? Is half the depth of the tank ok? The depth of the overflow has to match on the inside tubing and the outside tubing correct?

Also what kind of GPH rating am I going to get using the 1" PVC? 1.5" ?

 

[rallysman]

1/2 way is fine. That's how I'm running the one on my 265. With 1" you can get around 600 gph, and I'm not sure about 1.5".