How long do CYA turbidity test chemicals last?

[G$]

Like the title says, what is the effective age for CYA test kits? I think mine is 3-4 years old. (Reagent R-0013)

According to my cheapie test strips, my CYA is "at or over 100". But according to the vial test, it is between 60-80, and very likely right at 70. (I ran the test twice and think 70 is the dissapearing point) I of course trust the vial test more, but I do wonder about the reagent age.

Also, in general, how long would all reagents remain effective if stored out of sunlight?

 

[Bama Rambler]

That's a commonly asked question and the CYA reagent is probably the most stable. Even with it, 3 to 4 years is a long time. I'd order a new bottle if it's the oldest or it might be better to order a complete refill kit if the entire kit is that old.

 

[Butterfly]

Also, in general, how long would all reagents remain effective if stored out of sunlight?

We have found that, when stored properly, they should last several years. More info here:
extended-test-kit-directions-t25081.html