When I first started getting tadpoles (which wasn't long ago, my frogs just recently came of age LOL), i was using tap water that I let sit for 24 hours. I had a lot of tads die though, especially after they first hatched. So then I read about the leaves and that oak leaves are good to put in with tads. So I soaked some oak leaves in the water overnight before I put the tads in it....then more tads died. Finally I started getting RO water, no leaves, no nothing, just RO water and of course their food was in it. Now I rarely have a tad die, even when it is very small. I wonder why everyone has such different experiences with this?