Based on the instructions that came with my skimmer and my under standing of how a skimmer works I set my skimmate as dry as I can. For the most part surface tension grabs the waste and pushes it up the skim stack. The wetter the skimmate the weaker the surface tension the clearer the water. So I assume that dryer is better, even if it takes longer because it can remove heaver waste. Now is it better for growth or color you got me on that I don’t know.