Egg crate

[kookie_guy]

Originally Posted by ALang

Egg crate as tank screen may reduce a substantial amount of light going into your tank, if you have photosynthetic animals, that may be a concern

Not really. It can actually help focus more light into the tank. If you've ever looked closely at light diffuser panels, you'll see that the suqres are not even on both sides. There's actually a top and bottom of the sheet, depending on what you want. There is a slight taper to the holes. If you put the narrower end down, it will help focus the light into the tank.