Whatever you do, I would NOT reccommend a prizm hang on filter by Red Sea!. I bought one thinking it was going to be great, and was dissapointed at what I got. I sold it after 3 days of headache. You would think for what you pay it would work well, but I wasn't happy at all! There are a few others that are hang on, but I went with a skimmer that fits in the wet dry. Good luck.