Im not really sure the measurer i have is really old and can give really inaccurate readings, so i dont really use it and i have just been going by eye. I have woodchips as his terrain and i know the wood can hold water pretty well, the petshop told me if i got the wood then humidity wouldnt really be a problem but i think i might have been told a lye. Honestly its probally not at the best level or what it should be.