Penn-Plax Cascade Mini Hang-on Aquarium Filter With Activated Carbon and Sponge For Small Aquariums Cleans Small Up to 7 Gallon Tank

Works great on my 3.4 gal. Very small, for some reason I was expecting it to be a little bigger but its cute and works great. The insert is no good. But I left it in for now. I shoved an aquaclear (20/30) bio media bag in it and it just fit. Of course that media goes in a much larger filter so even if I removed half of it. And used filter floss with it. It would work great. For now just the media is working for me and it's quiet with great flow. It says it will work up to 7 gal. An I'm sure it would. But I would only put it on 5 gal max myself.

Defective product. The filter did not start at all. Seems like the wiring or plug is faulty.

Such a tiny power filter!!! Who knew of such a thing existing??? Works great, easy to clean, keeps my 3 gallon long tank sparkling, and makes the water move alittle, too, which the fish seem to appreciate.

Nice and quiet, although outlet not as adjustable as advertised. The intake should be fully submerged, or the motor becomes damaged and sounds awful

Very bad product. Couldn't even withstand half an hour run time. It just stopped working. request for return and no response yet. So in case the piece you get is bad, forget your money.