I finally got tired of relying on the guys at the pool store advising me on how to treat my pool. I've been fighting to keep FC levels up for two years and they never told me my cya levels were off the charts and a cause of my problems. They just kept selling me stabilized chlorine. I've been adding more and more chlorine (now using cal chlor) to keep the levels at barely readable levels. So far, the pool looks great, but at a heck of a cost. This summer I found this site and I'm learning. A lot. I got my TF 100 test kit a couple of weeks ago and am learning how to use it.
When I test for cya, I only know that my levels are way over 100, but is there a way to know the exact number? The liquid in the test tube is about half way between the bottom and the 100. I'm planning to drain water off the pool to get the cya level down. Any suggestions on how much I should drain? Also, what are my next steps after I drain and refill?
Thank you all for the help you provide.