Okay I lied, I checked my store and it's only seven dollars. And that mini rapids works pretty good again I've heard a lot of bad reviews and it did leak out of the side for a small amount of time, but overall it's worked well for me. And I like it better than the hang on the back filter types because that water would go straight down into the middle of my tank and mess up the substrate. This I can put that spray bar just under the surface so there is good water circulation but doesn't move the top of the water. That way, very little CO2 escapes .