Can CYA testing agent R0013 go bad?

[accountingmama]

Can CYA testing agent R0013 go bad?

We purchased our TF-100 kit in late August, early September of 2014. I have been doing my testing without difficulty.

When we opened the pool the beginning of May 2015, I was getting some consistent CYA readings of 40.

I all of a sudden starting getting CYA readings of 20.

I took my water sample to the local pool store for their "free" professional water testing and their reading came out at 38.

Here is my concern:

Last year were we were consistently around 30. We drained our pool in the fall to below the skimmers and added water in the spring. We recently just got 2 inches of rain as well. Not sure if the testing agent could be bad, resulting in the false reading or could the added water along with the rain last night change the CYA that much? I store the kit in the garage.

Tonight I just added stabilizer to add 10ppm to see if I can get a different reading tomorrow. I'm also going to order a refill kit for my TF-100 as I am almost out of the R0013.

 

[JasonLion]

The CYA testing reagent can go bad, but that normally takes several years to happen.

One possibility is that you got a false low reading because of cold pool water. When the water is cold you should let the water sample warm up inside before testing or the CYA test can sometimes read lower than actual.

 

[duraleigh]

Tonight I just added stabilizer to add 10ppm to see if I can get a different reading tomorrow.

Granular stabilizer will not show up on a test for up to a week after adding. No point in testing tomorrow unless you put in liquid stabilizer.

How often are you testing?

 

[accountingmama]

I have tested about once a week and brought the water in to warm up when it was cold. Right now the pool is averaging around 80-84. I put in a fast dissolving (phoenix brand) stabilizer in yesterday only enough to go up around 10ppm. This way if I was correct at 20ppm, I would be closer to 30ppm and if my R0013 was bad, I would be closer to 50ppm (no too high).

I tested today and the CYA level was around 30. I only have enough CYA agent R0013 to do one more test. Ordering refills tonight, so hopefully we'll get the new chemicals next week.

I'll probably test on monday (if I can hold off that long - I think I am becoming a testing junky).

Thank you.