Will CYA reagent go bad?

[kris77]

Hi all,

I've been using the same bottle of R0013 for a few years now. Usually when I open my pool for the year my CYA levels are very low due to draining the water below the return and having to refill. This year however, I opened with a CYA of 40-50. My neighbor has the same pool as me and I help him every year get started and his tested the same...50 CYA level. This isn't the norm for us and I was just wondering if my reagent might be bad and causing a bad reading.

We do toss in 3 chlorine tablets in a floater as soon as the pool is uncovered and while it's filling back up. This usually helps to add a little to the CYA number, but it's never been at 40. I usually have to add about 4lbs of stabilizer each year to get it started. Just want to make sure I'm doing things correct and it's not going to mess me up.

 

[Dirk]

How you store your reagents can make a difference. Your mileage may vary. From Taylor's website:

Shelf life
You will find the expiration or best by date printed on the label. As with other perishables, reagents and test strips must be stored under controlled environmental conditions. Listed below are some simple rules to help ensure accurate test results:

• Store all reagents and test strips at a consistent temperature between 36°F–85°F (2°C–29°C).
• Keep all reagents and test strips out of direct sunlight.
• Store all reagents and test strips away from treatment chemicals.
• Always replace caps tightly on reagent bottles and test strip containers.
• It is best to replace your reagents and test strips seasonally.

Both Taylor and TFP recommend refreshing test reagents once a year.

The bottom line: if you find your FC dropping faster than expected, that would indicated your CYA is not doing its job (it's low). If you find your FC holding as expected for any given month, then your CYA is fine. As long as you keep your FC at your target level, and never below your minimum level, then an errant CYA test result is "not going to mess [you] up."