I've got four different types on my tanks: I've got a Remora on my 46 and it does great. On my 55 I've got a Red Sea Prizem which is so/so, I wish I didn't spend the money on it, but it works, you just got to keep on eye on it after water changes. (Here comes the beat down) On a 20 I've got a Seaclone 150 that I've had for about 10 yrs and mine works like a champ. Pulls out dark skim and I clean it out about twice a week. I like it. On my 29 I've got a Seaclone 100 that sucks, I wish I would have got something else. So in order: Aqua C
Seaclone 150
Red Sea Prizem
Seaclone 100
I know everyone else hates the seaclone, but IMO, the 150 works .