Pur-Blue Dye Indicator

10 mL bottle of Pur-Blue Dye. Test how many hours you’ll need to leave SolarBag® in the sun for first time use in any location. Squeeze one drop of Pur-Blue food grade dye into a full SolarBag and see how long it takes for the color to clear. Photocatalysis breaks down blue dye at the same rate as contaminants. Test again when changing climates, or if clouds cover the sun for days. (Test SolarBag performance after a year of continuous use, because twigs or debris in water source can cling to mesh and reduce performance over time