One thing to remember, is that glass will keep a good bit of the heat in your tank. I have a 70gal tank, and for the longest time had 2 glass tops on it. I always had trouble with keeping the temperature around 78-79, and always caught it at 81 and even sometimes 82 degrees. Since I installed my overflow, I don't have a top on at all. If it was me, and I didn't have a chiller to keep the tank cooled, I wouldn't use the glass tops. Also, keep in mind that if you a have a jumper in your tank, you could come home to them carpet surfing lol.