Chase's 31G Tank Starting to come together :D

[outacontrol]

the problem with restricting the overflow at all with a ball valve, is that if something like a snail or fish or anything large enters your overflow pipe it well get caught on the ball valve and then block or restrict the overflow.
Without an emergency overflow to then take the rest of the flow, your return pump will drain your sump, overfill your tank, flood your parents house and possibly burn out (from running dry) your return pump.