By the way, my chickens slow down on water drinking when there is algae or mold present. I think they can taste it and don’t trust it much, and yeah, it can cause runny poop. I clean the waterer with diluted bleach water when I suspect it, and soak the nipples for a bit. I rinse until I can’t smell the bleach anymore. Problem with mold and algae in waterers is if you get it once, it seems to return no matter what. I stopped using our garden hose to fill the waterer once I figured out that mold and algae will grow inside them. Now I use the kitchen faucet.