what causes brown water
To eliminate brown water, you have to first delve into the root cause. If only your water heater produces brown water, then the most likely suspect is a damaged anode rod that needs to be replaced. A malfunctioning water heater or the boiler system in your building may also cause water to turn brown.
Quick Answer. Pool water turns brown due to high iron levels. Water from certain sources, such as wells, contains dissolved iron that oxidizes readily and turns brown when in contact with air. Acidic pool water, on the other hand, deteriorates metal equipment in the pool, introducing excess iron into the water. Continue Reading.