The tank might fill over the outlet of the hose. A loss of water pressure may result and back siphoning may occur when a hose or faucet is submerged. The entire water system may become contaminated by impurities or poisonous solutions. Livestock should never be forced to drink dirty or contaminated water. Stale water can still cause a reduction in water consumption.
Dirty water is a host for disease organisms.
Disease can rapidly spread if animals drink from the same trough. If an animal becomes ill it should be isolated from the trough and the trough should be disinfected and cleaned. Sprinkling baking soda into the fountain periodically may reduce algae growth. Have an elevated base around automatic waters. Make the base wide enough so they can easily put their front legs on it but not their hind legs when they are drinking.