Humidity issues

[Adiowns]

So I have a desert terrarium set up for a hadrurus species of scorpion, but as you all know humidity is a problem for desert species. I have a heat pad and am getting a new heat lamp soon, but for some reason even with the screen on top the humidity is still at around 70 % +. Is there any way to lower the humidity without having to modify the top of the tank? Thanks in advance

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