This may have been obvious but I have never found it explained anywhere. I have a planted white's tree frog tank, with a false bottom, drainage layer, and waterfall, that I mist daily. Recently, due to the annoyances of the waterfall, I was thinking to myself what exactly the purpose of the drainage layer was, especially considering that the waterfall drains in one pretty localized location. Misting seems to wet the surface of the terrarium but that's mostly covered in moss and so I doubt that moisture ever reaches the substrate. This leads me to the question, do people water their tanks, and if this is the case, do they find that their moss and or plants thrive better under this arrangement?