Copper, iron or manganese pool problems
Pool water problems - copper, iron or manganese
Copper, iron or manganese in swimming pool water all cause the water to discolor without affecting the water's clarity much.
If the water changes color after chlorine (or any other oxidizer) is added, the swimming pool water probably contains a metal.
Which metal is in the pool water?
Green pool water - usually copper or sometimes iron
Brown pool water - iron (occasionally copper)
Purple/ black pool water - manganese
What to do about metals in pool water?