Also, welcome to the world of worrying about humidity
That dirt/coconut stuff will start off humid as all get out, but once it dries, it's much like other substrates..you get to spray a lot. I use a humidifier in the house when it's dry like this and I'm still spraying daily. I'm reconfiguring how to cover up most of the screen, since I want it to come off easily as well. Easy way out is some type of plastic over the majority, and lay off the lights...but a red bulb seems to be the best way to keep ambient temps up on my tank (until I get the cash for another uth and rheostat).