Shredhead
05-11-2015, 12:15 PM
Powder turned dark grey/black during the winter.
Is it still usable and accurate?
PoolDoc
05-26-2018, 02:59 PM
This is a common issue, so I deleted a somewhat inaccurate answer.
Briefly, if you can get a pink color, you should be able to get a somewhat accurate reading . . . but dark, black, or hard reagent powder should be replaced.
The the complete answer, is here:
http://www.poolforum.com/pf2/showthread.php/26677