So my vertex protein skimmer is sitting in about 7.5 inches of water in my sump and only producing about 1/5 cup of skimmate every 3 days. The skimmate is pretty dark and smells disgusting. My aquarium has been up and running for about 4 months now. It is a 75 gallon aquarium with about 80 lbs of live rock with two small tangs and a niger triggerfish. I have the water level set to right at the bottom of the collection cup. Should i be producing more skimmate then this?