6 - 1 lb bags. Kills bacteria & algae. Formulated for vinyl pools: Improves filter performance; swim-ready in 15 minutes (Refer to the re-entry statement on the back panel for further guidance). Clorox Pool: Free App: Water testing & solutions center. Questions? Pool care tips? 1-800-Sos-Pool/cloroxpool.com. how2recycle.info.