i dont know if this has already been addressed but anyway... TO ANYONE INTERESTED IN INCORPORATING A FILTER SYSTEM, I HAVE FOUND A FILTER THAT IS QUIET AND DOESN'T DISTURB THE SURFACE OF THE WATER. IT'S A TETRA WHISPER IN-TANK FILTER.
That's what I have in my five gallon, and I would defiantly recommend it. It's very quiet, calm, and even cheap. I'm thinking of switching my other one to a whisper, because my current one disturbs to water quite a bit.