I got the Artica 1/5hp for my 200 (150 top/50 refugium) and it works like a charm. It's very quiet but does create quite a bit of heat... whew. It's plumed through the wall into my bathroom closet and pretty much heats the whole bathroom up about 10 degrees when it's really working. Seems to only run about 2 hours a day. Paid about 550 for it. Good luck...