Shock, Xtra Blue Crystal clear water. 6 in 1 formula. Kills and prevent algae with algae-fighting crystals. Kills bacteria. Improves filter performance. Swim-ready in 15 minutes (Refer to the re-entry statement on the back panel for further guidance). Fast-dissolving. Easy open. Easy pour. how2recycle.info. Questions? Pool Care Tips? 1-800-Sos-Pool. cloroxpool.com. Free App: Water testing & solutions center.