Lighting through a glass top?

[banditpowdercoat]

Hmm, in doing some testing with a sheet of eggcrate and my Tek light. The eggcrate takes away a little ligth and reduces what little shimmer I have to nothing. The glass top reduces about the same light as viewed through the side of the tank, but the shimmer is still there. Just testing the difference in tank heat with/without the glass cover right now.