I have one in my Nano Cube deluxe. I put it in the left chamber in the back so it's out of sight. As for making this thing work it's hit or miss. I have noticed that the water level has to be just perfect, about 3/4 of the way up on the chamber, measured from the bottom. Even then it still doesn't work that great. I guess a little skimming is better than nothing. I can't imagine it could be much better on a 24 gal though, considering it doesn't skim that much. I think it's just a poor design. I know this isn't much, but your not alone on this one.