I filter all my tanks with 1-2 HOB's, 1 sponge filter, and I try to keep a powerhead in all my tanks to keep stuff moving around and to help break poop/uneaten food down. I like the penguin 350's because I can get them for about $26 price matched at petsmart. I fell all of my extra spaces with scrubbies and loofas. My local dollarstore has mini/medium sized loofas 6/$1 and they are AMAZING.
My best filtered tank.. I have one tank upstairs in the main part of the house that was filtered with a penguin 350, and a hydro 5, it ended up turning green because it was getting to much light. My parents hated me for having my "filthy tank" up stairs. I painted 3 sides of it to make them happy and it was still green two weeks later so I went out and bought a xp3. I have a 12" red devil in the tank for now and its by far the cleanest tank I've ever owned. Too bad I'm going to steal the xp3 out of it tomorrow..
anyways.. 60gallon
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1- marineland penguin 350 w/ stock media + scrubbies
1- rena xp3 w/ stock media (have new media, haven't tried it yet) 1-
hydro 5 sponge filter powered by a penguin 350gph powerhead