humidity is in the low 30%to 40% how can i raise it?

[wolfy-hound]

The screen lid is letting all the humidity out. You'll need to cover it with tinfoil, taped into place, over at least half, up to 80%. Heat lamps dry the air a lot, and having two is probably drying all the humidity out very quickly.

It sounds like you have a LOT of heat on that one tank. Two heat lamps plus a UTH sounds like overkill. Do you have a accurate way to read the temps? Do you have a regulator of some sort on the UTH?
I hope this helps, and there is a sticky on using a tank to keep your pet in, and it describes how to cover the top.