well i spray my tank every day just to keep the hum. at 50%, and also pour water in the subtrait to dampn the soil and then it drys out by evening and more so when shes about to shed. My house is super dry, older home. I do already have the plastic overtop of the tank.. and i have no idea what kind of subtrait i have.. but i have taken some pictures to give you a better idea.. hope this can help and pick out what soil i do have already and if i should just get some more after a couple of weeks of using newspaper.. thank you