GardnClean Liquid Mix Chlorine Dioxide (CIO2) Disinfectant & Sanitizer - 12.5 GallonsBest In Class Chlorine Dioxide Sanitizer, Disinfectant, Line Cleaner + Continuous Water Treatment Gard'nClean GC Liquid works by releasing chlorine dioxide gas into the solution once the sachet is added to water. The generation vessel and storage container must be sealed to prevent the ClO2 gas from escaping. Available Sizes: 2 Gallon Makes 2 Gallons of 100 ppm Solution 12. 5 Gallon Makes 12. 5 Gallons of 100 ppm of Solution 30 Gallon Makes 30 Gallons