In The Swim Spa and Hot Tub Metal Out - 1 Quart

In The Swim Spa and Hot Tub Metal Out prevents and removes mineral stains caused by iron, copper, and magnesium. It also prevents the build-up of scale around the water line and in the plumbing. When minerals oxidize they discolor, after discoloration if the mineral settles on the interior it can leave a stain. Iron will go red/brown, copper will go purple/black, and magnesium is pink/purple. Metal Out is a must for areas with heavy iron/copper content or well water. Dosage: 16 oz per 500 gallons. A double does is suggested for stubborn stains. In The Swim Spa and Hot Tub Metal Out should be applied directly to the spa/hot tub water at a rate of 16 oz. per 500 gallons with the spa/hot tub circulation system running. Allow the spa/hot tub to circulate for 3 - 4 hours. Regular brushing is suggested and encouraged. A double does is suggested for stubborn stains and scale. Active Ingredient: Hydroxyethylidene Diphosphonic Acid (HEDP) 5 - 6%