Pristine Blue Pristine Clean prevents metal staining in pools and hot tubs. Pristine Clean prevents the metals that enter your pool or spa through hoses, jewelry and metal equipment from attaching to the walls and leaving unsightly stains. This product also has been know to lighten and remove existing metal stains. Product Dosage For Pools: 2 ounces per 10,000 gallons of water every 2 weeks. Fro Spas: 1 milliliter per 100 gallons of water every 2 weeks. Directions For spas and hot tubs apply at a rate of 1 milliliter of Pristine Clean per 100 gallons of water every 2 weeks. For pools, apply at a rate of 2 ounces of Pristine Clean per 10,000 gallons of water every 2 weeks.