we run a prizm HOB on our 29g reef and it works great, i hear they suck all the time, but i dont think so. it pulls out a TON of brown stuff from the water everyday, and im very happy with how well it works and how quite it is. and it only cost us a few frags from someone local, so not a bad deal at all. if you have $200 to blow on a better one go for it, but if you want something that works really good and dont want to spend that much, i would get a prizm.