I plan on getting a 30 gallon eventually. What brand of powerhead do you use/prefer? Are there any to avoid? I was thinking either AquaClear, Penguin or Maxi-jet, but I'd appreciate some input.
Depends on what you need it for. For driving a sponge filter or RFUG filter, or if you need the venturi function, penguins are my favorite. If you just want increased flow, I'm a huge fan of the Koralias.
I'd probably use a Koralia 1, myself. I like the fact that the flow is more dispersed rather than a straight jet coming out. They are also very difficult to clog (I have messy fish).