Check the listing for details. BioGuard Arctic Blue Swimming Pool Algae Protector 32 oz. Condition: New. Listed at 41.99 USD. Arctic Blue Winter Algae Protector prevents and controls algae during the winter months when the pool is closed. Dosage: Perform a complete water analysis and balance according to local pool dealer's recommendations If metals are present, treat with BioGuard Pool Magnet Plus according to label instructions Allow the pool to circulate at least 1 hour before adding other products After pool is no longer in use, add BioGuard Arctic Blue Winter Shock according to label directions Allow pump to circulate for several hours or overnight Add 32 oz. of Winter Algaecide per 15,000 gallons directly to the pool with the pump running Add around he edges so that it is evenly distributed Allow to circulate for a few hours Clean pool water line, shut down filter, drain pump, and winterize as per manufacturer’s instructions Cover with a solid cover if possible Pools without a solid cover may need a second treatment later in the non-swimming season