Vertex Aquaristick IN-80 Question

[CherylMcKay]

I have a Vertex IN-80 that is skimming to the extreme. I have had it installed and running for about a month now. I did have to remove the sump to fix it and drill it but I was still running with a fluval filter.In 2 weeks I have probably changed out 40 Gallons of water in a 75 Gallon tank with a 30-35 gallon sump. It skims so hard the water in the sump has a layer of foam on it.... I would love some advice as it is driving me nuts. I don't think the water still has that amount of disolved proteins in it but I am unsure what I should be checking for or if this skimmer is just not the right one for my sump.

Thanks