Water Test Reagents - Further Reading

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Water Test Reagents

All water test reagents have a shelf life. Powders and crystals are very stable if kept dry. Acids will also last a long time. Storage conditions are more important then date of manufacturer for reagents[1]. Taylor reagents are formulated to last at least one year.

Best Reagent Storage Conditions

  • Store reagents at a consistent temperature between 36F-85F (2C-29C)
  • Extreme fluctuations cause reagents to deteriorate
  • Keep reagents out of prolonged direct sunlight
  • Replace caps immediately after use to limit exposure to air and humidity
  • Avoid switching bottle caps
  • Keep reagent bottle tightly closed[2]

Recognizing Bad Reagents

  • R-0002 DPD #2 - should be colorless; as it goes bad it will change to pink then brown[3]
  • R-0003 DPD #3 - should be colorless; as it degrades it will become yellow
  • R-0004 pH Indicator - as it degrades it turned from red to yellow or purple
  • R-0008 TA Indicator - should be dark green; begins to stain the milky bottle as it goes bad
  • R-0011L CH Indicator - should be deep blue color; any other color indicates it is bad
  • R-0718 Silver Nitrate Indicator - should be colorless; no easy way to tell if bad and recommended to replace annually
  • R-0871/R-0872 FAS DPD - Should be colorless; if bad will become increasingly yellow

Other Test Equipment

  • Wipe all equipment with a clean dry cloth after use
  • Make sure color comparator is in good condition with no fading or staining
  • Test vials should be clear and not cracked