my bullhead is not messy at all. i had a bullhead, two gar, 4 pumpkin seeds, and two coppernose lugill in a tank at once in a 120 gallon and it was still just a weekly 25% and a flilter cleaning every two to three weeks. my water was crystal clear. the other nice thing about them is you dont need to heat your tank. one less thing to buy and less electricity to pay for.