My TF-100 kit was bought 1.5 years ago. Never tested CYA in my pool. Was confused by the directions and for some reason never attempted it again till today. Kit has been kept mostly indoors until I loaned it to my bro, who has left it outside in the shade for about 2 months. This week, it reached the 90's.
Decided to test my bro's CYA and it was zero. My CYA is also at zero. What are the chances the reagent is still good and the reading is correct? My bro's pool was green for almost a year. I read another post that bacteria can eat CYA and turn it to ammonia. That may explain my bro's reading. My pool however has been mostly blue since I bought my kit and found this site. And I know when I bought my house, the pool was green and I hired pool boys who slammed it with powdered shock. CYA's must have entered the pool chemistry then. I can go to Leslie down the street and have them test my pool free. I can maybe ask my neighbour for a sample of his pool water to test my kit to see if I get a reading.
Question is, given the conditions my bro kept my kit in in the last two months and the age, should I just get refills anyway?