I was praying for rain a few days ago and now I'm ready for a break. I have a pond and I put a little bleach in it (¼ tsp to 1 gal of water). I have a pump in it and circulate the water. The bleach will dissipate from the sun, which is out right now. Birds and squirrels drink out of it and so far no problems, but when we had our camper we would put a little in our water tank and if you are on city water it is chlorinated.