how many times a hour should the water go through the sump?

[banditpowdercoat]

That goes back to what I was saying about Every tank being different. If you do not want to use Powerheads, consider a closed loop. An intake is real easy to guard. Best thing is T the intake off a few times, then there is little suction at all the intake inlets, not just one. If you flow to much through a sump, regardless of skimmer, your going to introduce microbubbles. part of a sump's design is to be slow enough, add time/passages to let the microbbbles escape.