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

[freezetyle]

Originally Posted by Mr OM

If you skim it 100% then what you return to the tank is clean, if you skim 10% of it then 90% of what you return is dirty or unskimmed, why would you do that when it costs more money in hydro and pumps to do worse?

I understand that. But say, someone was using there return pump for extra flow to their tank. The extra water movement through there wouldn't technically affect the skim-mate that is pulled out of the water.

That being said, there is no actual way to test out these theories as a skimmer pulls out skim-mate in both situations. This test would be almost impossible because everyones tank (or say a "test tank") would differ from one another so getting a control would be practically impossible. I am not saying your opinion is wrong/invalid , I am just saying that in my opinion the flow rate through your sump isn't a big thing to lose sleep on.