Having difficulty in raising my CYA

[Zindar]

For weeks now, my CYA has measured less than 60 (using the R-0013 CYA Reagent bottle to test this). Since I have a salt pool, I'd like it up around 80 I think. I keep adding 3" chlorine tablets because somebody from this site told me that each tablet should raise my level about 4.3 ppm in my 7600 gallon above ground pool. I feel like over the last several weeks I've added 4 or 5 of those tablets, and I'm not seeing any CYA change.

However, could one of these three things be the problem?:

1) We've had a lot of rain, and several times I've backwashed to get the water level back down to the top of the skimmer opening, as the skimmer won't operate correctly when the water is past the skimmer hole.

2) My R-0013 bottle is a year old. Does those things go bad after a year?

3) My chlorine tablets are a little more than a year old. Do those lose their CYA after sitting in the bucket that long?


Well, I did just use up the last of of my R-0013, and I'm about to order another one, so if (2) above is the problem, I'll hopefully get a good reading soon. If you experts here think that (2) is something to worry about, then I better put a halt to adding those chlorine tablets, for fear of overdosing my pool with CYA.

 

[tim5055]

The rain and backwashing will reduce the CYA.

How was the reagent stored. if you kept it in the house at a fairly constant temperature with not spikes freezing or high heat I would think it would be fine.

The CYA is still in those tablets. It will be there for the next millennium.

 

[Zindar]

Yes, I've kept the reagent in my house the whole time. The hottest I ever let my house get (like when I'm not home) is 85 degrees, but 95% of the time it's much cooler than that.

So if it's good that means the rain and backwashing must have gotten rid of a hefty amount if each tablet really contributes that much CYA. I guess I should keep adding tablets then. I guess if I ever deplete the bucket and ever need more CYA there are other sources I can go to, but I figure I may as well use what I have on hand first.

I will say that a few weeks ago, I did get a measurement done at Leslie's Pool Supply, and they were in line with my own measurements.