General - Will Not Increase Algae Growthnatural Chemistry's Metal Free Enables Pool And Spa Owners To Eliminate Dissolved Metals That Cause Staining Of Pool Surfaces And Water Discoloration, All Without Adding Phosphates That Encourage Algae Growth Or Damaging Nearby Landscaping. Metals Such As Iron, Copper, Magnesium, And Manganese Can Cause Serious Staining Of Pool And Spa Surfaces, But Metal Free Easily Removes Them No Matter The Ph Level Or Temperature Of Your System. Perfect For Use In Any Pool. Excellent For Well Water Pools.