Does anyone have any suggestions on a good power head brand? I need one for my 120gallon. I got a small Hydor Koralia (nano) a while back for my 36 gallon and it just seems to create unsightly bubbles so I quit using it. I did like the magnet option however. Not sure if I get one that is larger for my big tank if that will be an issue or if there is a better brand out there. Would appreciate feedback.