CYA question...I'm confused

[kris77]

So to date, i've added 4lbs of stabilizer to my 15,000 gallon pool.

Added 2lbs at first, then the 3rd lb about 4 days later, then the last lb last Wednesday.

So its been exactly 1 week since the last pound was added, a week and a half since the pound before that and a little over 2 weeks from the first 2lb. This is a new fill and I had a CYA of 0 when I started.

I tested CYA tonight and at 20 the dot is completely blurred out. At 25, I can barely make out the dot, and at 30 I can see it pretty well.

For adding 4lbs of CYA, I'm only getting a reading of 20-25. That doesnt seem right to me. And i'm using about 3-4 ppm FC every day....Even with the solar cover on all day.

FC tonight was 3.5, CC was 0, PH 7.5

I added 60oz of 12.5%. Which should bring me close to 8 on my FC. I'll wait 45 min and go back and test. I've constantly loss less than 1ppm every night and the pool is CRYSTAL clear.
The CYA is confusing me though...

Any suggestions?

 

[Richard320]

When I crunch numbers on poolmath, I see an estimated value of 36 CYA for all you've added. Since the test is only good to +/- 10, you're within tolerance. Did that CYA say it was 100% Cyanuric acid? There are some blends that have borates in them.

Add another pounds, or use a few pucks to raise it a little if it worries you.