I went through the mill with this one a long time ago. The fruit tree netting was UV resistant, but you could Free Willy through the mesh. Doubling it up didn't help since the weave was meant to be forgiving, I ended up with 1/4" on one side and 1/2" on the other........of the same screen. Regular window screening made the hundreds I shelled out on the three-times upgraded lighting look like the tank was in a permanent fog. I finally found 1/4" screening used to cover ponds. UV resistant and everything. Only problem was the smallest was a 9' X 12' section that I ended up giving away 90% of over the next couple of years. The BRS stuff is a simple one-stop solution.