Efficiently reduce phosphate levels and clear pool water with SeaKlear 1040120 PhosKlear 4000! This eco-friendly formula combines two SeaKlear technologies to quickly remove phosphates and clarify pool water. Perfect for opening and closing pools, weekly maintenance, and compatible with salt systems. One quart removes up to 4,000 ppb of phosphates per 10,000 gallons. Keep your pool looking beautiful and crystal clear with regular use.