The air pump is so horrible that it died on me! buy a different air pump with an air regulator valve. Also there is no bio-media and little space to add some, but I managed to put a small piece or a scour pad. other than that it is good. It helped my betta bowl clean(before I moved him),and I have it now in my hospital tank, and it keeps it clean with the replacement air pump(10-30 gallons with an air regulator)