Originally posted by attml
I have a CS6-1 and I keep the riser tube as high as it will go (just below the gasket) and mine sits in about 8inches of sump water.
calvindo,
Did you move the riser tube up as high as it will go? If you do this it should skim more. Also, make sure you take some warm RO water in a cup and stick the airline tube from the pump in it once a week. I get a lot of salt building up in mine and it slows the performance tremndously. The RO water will clear that out and it will skim much better! Also, make sure you clean it once a week. I get a huge amount of sludge building up in the throat of mine weekly which slows it down some too! If you are not feeding heavily or you don't have a huge bio-load it may just be caught up and there isn't much to skim also.
not sure if your familiar with the cs8-2, but the collection cup is huge. I probably can go 1 month+ without emptying the cup. I have the riser tube pretty high up, just not sure how high, but will measure in a bit. i feed my fishes about half a cube of frozen shrimp each day, so i dont think its much of a bio load.