To be honest, my Biocube little cheapie 30 dollar airstone skimmer is working like a million bucks now. I have to empty the cup daily as its almost full by the end of a full day. I notice it skimming the most generally after a feeding. The skimmate is real dark and at times thick so I know its picking up a lot of waste from the water. I have it in the first chamber before the water hits the filter floss and the chaeto fugium. Right now I'm very pleased with it and of course I will eventually get a venturi skimmer and pass this one along to the next beginner for a moderately cheap price. Only cost with it are the wooden airstones that must be replaced monthly. Very good for the price and does the job overall. I honestly would recommend it to anyone who doesn't want to spend a lot on a skimmer.