works but with very little output and is noisy as all get out. Requires frequent cleaning. once collection riser tube is dirty wont work at all. Put it this way, they say the Seaclone 100 is suppose to not be that good but I switched to it and it puts out 10x's the output, nastier output, works all the time and is much quieter. I still use the skilter with the valve completely closed (quiet) and no media just to ciculate water. use it to run activated carbon about every two weeks. Hell I use it to dose. I use it for everything except filtering and skimming. I hear its okay for nano systems like 5-15 gallons if you can stand the noise. wooden airstone at the bottom of the venturi is supose to make it work better.