I sorta did the same thing. I just got a roll of that adhesive material people line cupboards and stuff with(I can't remember the name of it..), cut it to size, and put it on the top of my screen. I cut a hole big enough for my heat lamp and ventilation. Since then, my humidity has stayed at around 60%, never going below 55. And I've stopped using my heat lamp since then too. It has plenty of ventilation, and temps stay fine without it. So that helps my humidity as well. And it can't be my area, cuz I'm in Canada. That cold dry place.