Why use screen tops? I use the glass tops from petco on all my tanks. They work the best with no guessing on humidity and the plastic piece that goes on the back of the glass can be drilled if your worried about ventilation. The only time I vent my tanks is when I'm trying to lower the humidity to help slow down breeding. With the glass tops the tank stays 80-90% on humidity. The only problem I have found is that they hold in heat from the lights but by using a bakers rack to hold the tanks it allows air to circulate around the tank cooling it in the process. Best of luck.Name: IMG_0007.jpg Views: 367 Size: 119.1 KBThis is one of the racks in the frog room.