I have a tetratec filter for sale....this thing flows water through two cartridges, one side of each pics of major particles, and the other side is a finer mesh that pics up ALOT of small particles....it also has a heater unit that you can plug into it.
Clears up water alot faster than an aquaclear can, and I like the fact that it has a heater where bigger cichlids can't hit it. It also has a wet dry filter with no moving parts.
Basically, power of AC filter....no noise, built in heater, Wet dry that works better than marinelands, and filters that cost less the emperors, and filter more....
Caleb