Well after lucking out three times being home when my exquisite wrasse has jumped out of my aquarium. I finally got off my butt and done something about it. I ran across a Video on YouTube while looking up screen tops. It is polycarbonate roofing for awnings and greenhouses. It is clear as can be and supposed to hold up to heat and uv. Basically just plastic channels. Got it cut in around my overflow and return as close as I could. Hopefully a cheap and easy life saver. Also have to see how it holds up in the long run.