EDIT(after typing this): Sorry about the long post!
This is my first post. I've been lurking for a while and reading a lot on the site. I really appreciate having a site like this to go to and thank you all for sharing your wealth of knowledge.
The background on my pool situation is this. I moved two years ago from a house with a 15' above ground pool that required very little effort to maintain to a house with an in-ground pool. This is my third pool opening on the in-ground since moving. The first year was a blur but I was mostly happy that the pool didn't use much chlorine. The second year it dawned on me that this was a problem. Other than shocking I've only used about a 1/3 of a bucket of 3" tablets for the first two years combined! The free chlorine level is always over 10 ppm.
I've always taken the water to the pool store for testing and taken daily ph and chlorine checks myself. The pool always needed Alki and ph increase on opening, after that the pool has always sparkled and never had any algae. Last year I mentioned to the pool store that I never add chlorine, other than shocking, and that the chlorine level always stays high. They said it was because my stabilizer level was too high. It read over 100 last year. They use the computer testing machine that read the dip strips.
So fast forward to this year, after all of my reading on this site, I was prepared to do partial water changes to lower the CYA level after the pool was opened. I took off the cover, the water was a little cloudy but I could see the bottom. I added one 5 gallon liquid chlorine from the pool store and let filter run for 24 hours. The next day the water was mostly clear but something was off so I took a sample to the pool store and found I needed the alki and ph increase once again. They recommended 30 lbs of alki increase, I put in 20 lbs and waited to retest the next day. The next day the pool water was crystal clear and sparkling. That was 2 weeks ago and the chlorine level has not dropped yet. I went back to the pool store and did a water check, it came back perfect they said. Here's the results:
TC = 10 (max reading)
FC= 10 (max reading)
I asked about the CYA drop from last years reading of over 100, they said it could be from evaporation and rain, they have seen it before. I find that hard to believe in a 25,000 gallon pool. I was at my wits end with the pool store and ordered the TF-100 test kit I read about here. It arrived last night and here are my first results. I'm pretty anal about test procedures so I didn't have too much trouble with the readings, believe it or not the pH was probably the toughest for me. The CYA test is pretty tricky so I repeated it a few times and even surprised myself each time it read the same. The TA test was also a little tricky as the color blipped red earlier in the count but I assumed it must stay red when you end the drop count, please correct me if I am wrong.
The water temp was 76.
TC = 17
CH= not tested
The pool water is still perfectly clear but I need to know what to do about the high chlorine level and the lack of chlorine usage. I should probably bring down the TA also?
Thanks again for helping me out