I have a 10 gallon quarantine tank I use a small sponge filter with. It mounts on the inside of my tank with 2 suction cuts and yes I have to have a small air pump to operate it. It has made a world of difference in my tank!!!!!!! I couldnt find one of the small sponge filters around here and when I went on a resent trip to Lexington,KY I went to a petsmart and they had one. But our walmart has now picked up the almost exact same thing now. It is just so simple to use and also it took no time at all for my sponge to collect the bacteria to colinize. I simply used my old ornaments out of the established tank and put the filter on the wall and put the ornament right up against it and added some of the plants also to it. I will say that I dont know why but my tank never spiked anything and was established within a wk!!!!!!!! I find that very hard to believe but my pagota house was pretty nasty with alot of good bacteria! It was the easiest tank I have ever done. And lord knows that I havent even been doing fish a yr yet and I have had horrible problems with cycling a tank but this one was a breeze!