Hi all, here is a link to my 90g tank. 90 gallon aquarium*** SOLD - Great Lakes 4x4 . I bought this tank a few months ago and have finally got it up and running. My problem is that I have had some smaller fish in the tank and the overflow at the back of the tank is big enough to allow those smaller fish to slide through. I have heard about a comb that you can place over top but haven't been able to find one. Anyone had this problem, know where I could get one of those combs, or have any other ideas on how to keep my fish in my tank. The obvious to get fish big enough that they won't slide over, but I was looking for a few schools of smaller fish. Any ideas are greatly appreciated.