Cya super high


New member
Sep 3, 2020
My pool is approx. 20,000 gal. Had it drained and cleaned last spring after five years. The CYA seemed to measure very high after the company drained it. Thinking this guy may have put excessive stabalizer in it. Now it’s so high I can’t even measure.I use liquid chlorine and 2- 4 pucks a week. Appears I need to drain most of the water out and start over. Will that take care of it?

Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
Rancho Cucamonga, CA
Which kit did you use to test CYA? You should be able to get a result between 100-200 ppm by diluting the test sample using 50% tap water. Double the test reading for your final result.

A water exchange is the only (reliable) way to reduce CYA.

Each trichlor tablet you use raises CYA by 1.7 ppm. You may be adding up to 6.8 ppm CYA per week by using tablets. Stick with liquid chlorine bleach or install a SWG to avoid the same problems in the future.

Best of luck!

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Appears I need to drain most of the water out and start over.
That must be frustrating. :brickwall: Feel free to post a full set of test results with a TF-100 or Taylor K-2006C and we'll be happy to help you with any chemical questions. The diluted instructions for a high CYA can be found HERE starting at step 8. Good luck!

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