Check the listing for details. BioGuard Pool Magnet Plus 1 qt - 2 Pack. Condition: New. Listed at 51.98 USD. BioGuard Pool Magnet Plus is a concentrated chelating agent that ties up metals (iron, copper and manganese). This product removes fresh stains and prevents staining due to metals. Use this product monthly for swimming pools with metal containing fill water. Suitable for all pool types. Product Benefits: Prevents stains caused by metals Removes fresh metal stains Easy to apply Liquid chelating agent and stain remover Will remain effective for approximately 3-4 weeks (when used in accordance with manufacturer's instructions Dosage: Use 32 oz. per 10,000 gallons per 1.0 ppm metals up to 3 qts. per 10,000 gallons If pool has been shocked wait 24-48 hours before applying this product Product should be added when chlorine or bromine residuals is 1.0-3.0 ppm This products effectiveness is reduced when chlorine or bromine residuals exceed 3.0 ppm Apply directly to the pool water Use in conjunction with BioGuard Sparkle Up Temporary clouding may occur upon addition Maintenance dose is 3 oz. per 1,000 gallons every two weeks