Hope this review saves someone some trouble. I bought this kit for my children's growing goldfish, and the morning after I set it up it had pumped a couple gallons of water onto my kitchen floor. Turns out, the filter had somehow malfunctioned and was pushing water over the back of the tank onto the counter, then onto my floor, where it finally ran under my dishwasher and under my laminate flooring. Yes, the initial filter did malfunction. However, the mess could have been avoided if I had lowered the filter further into the tank using the clip that hangs it. There are three holes, USE THE BOTTOM HOLE! The filter has no lid and the only place for the water to go is outside of the tank. As far as leaks, I haven't seen any from the tank itself. The lid is also a little flimsy. Wal-Mart took care of replacing the initial filter with very little hassle.