TA is getting lower, PH still rising?

[Lando]

I have been using BBB for sometime now, things seem to be good except for my PH levels which seem to be at 7.8- 8.0, always rising in a few days if I don't add dry acid. In noticed my TA is getting lower from all the dry acid I have been adding over the course of a few weeks.

My TA is around 80 now and I would like to keep it at that level. How can I combat the creeping PH levels without further effecting the TA?

 

[JamesW]

If this is new plaster, the pH will rise somewhat due to that. I prefer to use muriatic acid instead of dry acid. Using a higher pH target will help reduce pH rise. I would use a pH of about 7.8. It is OK if your TA goes a little bit lower, perhaps to about 60 ppm, if necessary.

What are your calcium and cyanuric acid levels?

 

[Lando]

My CYA level is at 60 and my Calcium level is around 250. This is a old pool, 20+yrs. It's been really hot in central Florida the past month. I am guessing that's whats driving the PH up?

 

[JasonLion]

The most common cause of PH constantly rising is the combination of relatively high TA levels and aeration (which can come from fountain, waterfall, SWG, rain, kids splashing, and so on). Unless you lower your TA at least a little, the PH will most likely continue to go up.