CTX-550 Wintertar and CTX-551 Wintertar Liner Retains water quality from the uncovered pools during winter, avoiding the proliferation of algae and bacteria and the formation of limestone sediments.CTX-551C Wintertar POWER Special concentrated winter for liner or polyester pools that will allow you to keep water in perfect condition during the wintering period avoiding the formation of algae and bacteria. Save water keeping it all winter. Its revolutionary lid allows it to define the exact maximum dose by helping it save and use the product more efficiently. Maintenance treatment, Supercloration with granulated dicloro (CTX-200GR) CTX-550-Standard Winter (5LTS Packaging) CTX -551 - Special Winter for polyester (fiber) or liner pools) (5LTS Packaging) CTX -551C - Special Winter for Liner or Polyester Pools. (1LTS PACKAGING) Dosage :: CTX-550: 0.50 LT by 10m3 CTX-551: 0.83 Lt for 10m3 CTX-551c: 0.83 LT by 10m3