I took my pool water to 2 different pool stores yesterday for testing. Store A uses Taylor test kit, Store B uses strips with an electronic strip reader
A couple of notes.
1. I added 32oz of 8.25% bleach (1ppm) and 16oz 31% MA (0.1pH) between my tests and the pool store tests.
2. Store A does not use FAS-DPD for FC and CC, it is a color comparator using the Taylor kit and tube. The max level for Store A FC test is 5.
3. Store B. Total Chlorine is pretty close. However, there is no way FC is only 4.1 with CC being 3.4.
4. Store A TA test. The technician counted until the color switched to pink, however, it was not finished changing. I asked her to redo the test and count until the color stopped changing, then subtract one. This 2nd test resulted in TA=120. However, their test software convers this based on a "stabilizer correction" and reported 90ppm. What is this "stabilizer correction"?
5. Store B pH test is way off, I don't know what else to say about that.
6. My big concern...CYA. I measured 65 using my Taylor K2006 kit. Store A uses a larger tube (probably 50ml pool, 50ml reagent) with an up/down slider to test for CYA. She did this twice and concluded 100ppm. I expected about 65. Consequently, I'm concerned with the level of CYA in my pool.
On the CYA test. Please give me some more advice on how to properly read the test. I did my test outdoors, back to the sun and fill until I can't see the dot. Towards the end of the test, it is hard to know exactly when it disappears as it goes away gradually.