Before I sound like a bad pet frog owner, I do clean out my bowls. The humidity here is so low and my gray treefrog has a small bowl (because he's small) so I am having to add water twice a day. Also, this frog is so active but he almost never dirties the water; he's my perfect little frog. Yesterday I did skip the cleaning. Today I was running late for work because of school stuff so I refilled, with the intention of cleaning it when I got home. But the night before last night I cleaned his bowl. How could it have grown so big so fast?