Stability of r-0014 and OTO in general


Silver Supporter
Aug 22, 2017
West Palm Beach/Florida
I like to keep an OTO test kit in a cabinet that we have outdoors that is under shade but still outside in Florida. It is just easy to quickly check pH and TC. If TC is not a dark yellow then I add some bleach or do a more precise test. I am also noticing that pH test seems to register higher from that test than the one I store indoors.

So is R-0014 very susceptible to heat? I dont want to get a false high reading and be adding acid when I dont need to.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
I think if you replace it once a year for $2.49 you will be fine keeping it outside.

Here is what Taylor Technologies says:


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 life—storage conditions are more important. As with all perishables, reagents are sensitive to environmental influences and will last longer under controlled conditions.

To this end, we recommend:
  • Storing reagents at a consistent temperature in the range if 36°–85°F (2°–29°C); 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 strip pads.
Taylor formulates its reagents to remain effective for at least one year, with only very few exceptions (molybdenum indicator in liquid form is one; after four months old it should be tested against a standard periodically). As a general precaution, replace all reagents more than one year old, or at the beginning of a new testing season.