THD also sells fiberglass screen material, so no metal to worry with. I made a 10" wood canopy for my 125g. I have a hinged lid for night with just the moonglow lights on, I can close the top. I use a fiberglass screen on top so during the day, when I have the top open, no bugs get in. The screen is stapled on the backside so I can feed/clean/change water. The whole thing cost $40 and looks alot better than the old glass top.