5 year water preserver for our 55 gallon water containers.

Recommended by Top Emergency Professionals Water Preserver is the first and onlyproduct recognized and proven effective for 5 year water storage, registered and licensed by the federal and state EPA. Water Preserver is a preprietary formula of stabelized, pH-balanced Sodium hypochlorite with highlyeffective residual action that kills bacteris, viruses, mold and fungus Directions for use enclosed with each bottle. To be used with; New(unused), blow molded, rigid, all plastic containers made of virgin polyethylene resin (5 Year)

Water preserver must be used within 6-9 month of purchase.  Water in a barrel can be preveserved after that for 5 years.