DPD powder ( R-0870) has turned dark. Is it OK?

[Shredhead]

Powder turned dark grey/black during the winter.

Is it still usable and accurate?

[PoolDoc]

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