I know this is an old thread, but I'm just now seeing it.
@yitzysturtles - if you have a screen top and the lights are sitting directly on the screen, you should cut a hole for the UVB light to shine through without the screen. Screen material filters out the UVB rays.
There is an aluminum tape that we have used for mesh screens in the past. Found near duct tape. I tape and overlap the INSIDE of the screen top. I just trace around the light fixtures in the area I want them positioned before I apply the tape. Then I cut tape when I get to where my tracing is. Make sense? It never moves, I don’t have to hear rustling foil and I can remove or replace anytime I want. It looks neat and does a great job of keeping heat/humidity up. Just a thought because that blanket makes me want to grab my photo albums and pets and flee. Lol!