Cya issues

[Aimbdd]

So we replastered the pool last year, and had to add cya back in. We got it up to 45 and closed it in November to let the plaster cure. Opened it back up to cya of less than 30. I’ve used tablets and liquid the whole season, and can’t keep the cya at 40. Is it normal for it to drop more than 10 parts each month if not adding any? My ph also has to be adjusted every other day still to keep it below 7.9. Any thoughts? (Plaster is now over a year old)

24000 gallon free form concrete pool, built in the 50’s. Have a variable speed pump, and a de filter. Have a Hayward liquid auto chlorinator on a timer. (Currently not in use do to cya issues)
Taylor 2006

 

[Texas Splash]

A CYA loss of 10 ppm per months is a bit excessive unless you exchanged some water. When you say "tablets & liquid", what liquid are you talking about? Also, please update your signature with all of your pool and equipment info. It should come in handy as we help you further. Also let us know if you have an auto-fill and/or have needed to add more than normal amounts of water this season.

As for your pH rising, please post a full set of test results so we can help you with that one.

 

[mknauss]

Some CYA degradation is possible but not that much. Are you sure you do not have a leak or have had sufficient rain to overflow the pool?

Why are you not using a Liquid Chlorine device due to CYA?