my whole life, i have used the motor run water pump filters, like whispers and such. i went to my local store and noticed that he used primaraly the corner filters that hook up the the air pump. he says that the work just as well, as long as you have some water circulation. so, i have a 30 to 60 gallon air pump, hooked up to two corner filters, the biggest ones i could find. also, i have a submersable 30 gallon 130gph submersable filter. it circulated water well, and makes a little current in any tank. im really looking for input on what you guys think. will this be reasonably ok for a community tank if i do water changes? i usually do a 20 % water change on my other tanks ever two or three days. will this be ok, or was i misled?