i use a 12VDC fan to cool off my ballasts, which inturn cools of the bulbs, since my tank temp isnt out of control, but I only have the fan wired into a 12VDC wall adapter, and no regulators or anything. variable controlled fans are a must for precise temp. control, but for me, generic can work. right?
a degree off wont hurt. not me, at least.... and I prefer DC fans since I work in 12V all day, I am a 12V freak.