I used an air driven skimmer in my early reef keeping days. But as, danmhippo mentioned changing the wooden air diffuser every week or so was a real pain in the @*. Not to mention the cost of buying quality wooden air diffuser gets to be expensive. Also like danmhippo mentioned, every air diffuser you buy acts slightly different than the one you had before, and if you don’t position the diffuser exactly the same each time, you have to spend a hour or more fine tuning the skimmer, if you don’t adjust it every time, when you wake up the next day, you will find your collection cup overflowing all over the place. Way too much work and expense if you ask me.