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

[Bloodasp]

Am I going off topic here? The poster was asking how fast the turnover rate is suggested. And so is the analogy I was putting in there. A car is not separate from it's engine either. It may not be separate from your system but it contains a lot of your equipment. It may or may not be that the skimmer might be efficient with a slower turnover or not, believe what you want until a thorough study comes out about it. The skimmer isn't the only equipment in your sump some of them do need some lingering time to work efficiently at the same time they won't work well if the water was almost not moving.