I use Spring water for misting and soaking. The reason I don't use distilled water for misting is because I'm pretty sure that's what my old whites tree frog died from Though the windows of my terrarium never get build up from the spring water, I guess I'm lucky I do try to clean up the poo whenever I see it but, my frog is sorta a spaz because whenever I try to clean it out he lunges at my finger! He actually got my finger in his mouth several times