CYA shelf life and half-life

[rj2222]

Had two questions, one practical and one I'm just curious on.

1. Will leftover CYA in a resealable pouch from last year still work this year? Work but less effective? Not work at all?

2. I know this would depend on conditions, but what's a ballpark half-life of CYA itself?

Thanks for the info.

 

[Newdude]

When stored cool and dry, cya lasts 'almost indefinitely'. I can't say how long, but it's probably longer than we'll be around.

 

[ajw22]

1. Will leftover CYA in a resealable pouch from last year still work this year?

Yes

2. I know this would depend on conditions, but what's a ballpark half-life of CYA itself?

Read CYA - Further Reading

 

[rj2222]

New dude
AJW, I had read that one before posting which actually led to that question that I didn't exactly see answered in there. Am I missing it? Like how chlorine has a half-life of 35-40 minutes when it's in the sun. But maybe that data isn't out there and it's really just how it degrades when used with chlorine. Was reading how some people's drops to zero over the winter and read that article and it got me thinking.

 

[Newdude]

Was reading how some people's drops to zero over the winter and read that article and it got me thinking.

Empirically we see a drop of 3 to 5 ppm monthly. Some of that is rain dilution for most locations. In the hot climates they may see 15% loss monthly, with no rain.

I don't know of any studies on this but somebody might. Hang tight.

 

[rj2222]

Ok thanks, even that general bit it helpful.

 

[ajw22]

Was reading how some people's drops to zero over the winter and read that article and it got me thinking.

CYA in water would last forever if it was not for heat or bacteria degrading it.

I am not sure what you are thinking about and asking.

 

[rj2222]

New dude kinda summarized it enough for my curiosity with that 3-5 drop per month on average in the real world, so I'm alright I guess.

 

[wireform]

It more depends how heavy the pool is used and heated but also dependent on duration of time. You track your loss and that becomes your track record. It is a consumable.

 

[AUSpool]

CyA in general is a very stable molecule due to its cyclic structure. The dry powdered acid form will last forever if kept properly. It has a similar toxicity to magnesium or even regular old table salt that we use with our SWG pools. There are bunch studies about how it is degraded by bacteria in water processing plants which is kind of important given its applications beyond swimming pools.

 

[rj2222]

Thanks Wire, and AUS that's insightful so thanks.