Check the listing for details. BioGuard Pool Magnet Plus 32 oz - 3 Pack. Condition: New, Made in United States. Listed at 77.97 USD. BioGuard Pool Magnet Plus 32 oz - 3 Pack Brand: BioGuard - Item 23454-3 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/Features:* 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 instructionsDosage:* Prevention of Stains:** Apply 1 qt. per 10,000 gallons* Removal of Fresh Stains:** Ensure sanitizer level does not exceed 1.0 ppm** Turn pump off for 8 hours** Add 1-3 qts.