On the flip side, if you got tank water in your eye somehow be it from your hands or whatever, could the dirty tank water cause you to get conjunctivitis? One time I had put a fish bag in the tank, poured some tank water into the bag gradually and after awhile proceeded to take the bag out of the tank so that I could release the fish w/o the bag water into the tank. Well somehow when I pulled the bag out of the water I got some of the water in my eye and sure enough within the week I was at the Dr.'s office getting eye drops for conjunctivitis....coincidence?