All reagents have a shelf life, whether they are liquids, powders, crystals, tablets, or test-strip pads. If kept dry, powders and crystals are very stable; acids are also long lived. Date of manufacture is not the controlling factor when it comes to shelf lifestorage conditions are more important.To this end, we recommend:Storing reagents at a consistent temperature in the range if 3685F (229C); extreme temperature fluctuation, say from a refrigerator to a hot car trunk, causes reagents to deteriorate.Keeping them out of prolonged direct sunlight. (Note: their brown plastic bottles help protect very light-sensitive reagents.)Segregating reagents from containers of treatment chemicals.Replacing caps immediately and tightening them carefully so that exposure to air and humidity is limited.Avoiding switching bottle caps, placing bottle caps on soiled surfaces, repouring reagents into contaminated containers, or touching test s

• Replacement reagent for Taylor Pool and Spa Liquid Test Kits
• 3/4 ounce bottle of Orthotolidine Reagent
• Taylor Reagent Number: R-0600-A-DB
• As a general precaution, replace all reagents more than one year old, or at the beginning of a new testing season.