Which one do you do, dry or wet? And when dry skimming when you lower the bubbles in the chamber,does it actually rise high enough to make it in the collection cup? And one more question, right before the valve there is a little piece of plastic where you can put some airline tubing on it, what is that for, currently I don't have anything on it? Also I noticed that my skimmer is a bit noisy where the silencer is there is a piece of airline tubing that connects to the pump to the silencer and there is another opening on the silencer, looks like another place to add airline tubing is there anyway to make it quiet, I tried to plug it up but when I do that water overflows the collection cup and makes a big mess, please help!