Storing and re-using Taylor's reagents

[Water_man]

How does a degraded DPD-FAS powder look?

[aylad]

The more degraded it gets, the darker in color it gets, 'til it's clumpy and almost black. In my experience it still gives accurate results up to the dark gray, unclumped stage, but after that it needs to be replaced.

Janet

[Poconos]

I ran a test a couple years ago and the thread is here:

http://www.poolforum.com/pf2/showthread.php?t=4659

As for the reagents I do keep them in the fridge. Many years ago in an era known as BD, Before Digital, I did color film and paper processing as a hobby. Those chemicals, films, and papers are among the most sensitive to degradation. I kept all this stuff in the fridge and found all were perfectly good way beyond the published drop dead times. Cooling, darkness, and keeping dry, that is away from moisture and a source of oxygen, slows and sometimes completely stops degradation of chemicals.
Al

[waterbear]

The FAS titrant can also degrade. It if turns orange or pinkish instead of clear (like water) then toss it out and get a new one.