Huge TA and CH swing

[RPSalty]

I've been using the TFP app for a few years. My TA, once I quit chasing, has been steady 80 for months. The CH has been steadily dropping to 350 for even longer. The PH hardly moves, I add 1/2 cup acid once a week and maintain 7.8. (Keeping 7.8, not lower, is what I attribute to the TA steadiness. )
Today, CH is 1025, I tested it 6 times. TA is 40. Tested twice. I thought I had bad reagent 0012 (new bottle). Then I checked TA. Also of note the CYA dropped to 50 from 70.
Florida, there's been rain, but no more than accumulated 2" at my house during the last week.
I cannot imagine its the make up water, there's been enough rainfall to offset evaporation. What's my best course of action?

PoolMath Logs

 

[RPSalty]

I called the local P-A-P, all their pools samples are indicating low TA. Their data shows recent rain is acidic.

 

[reggiehammond]

CYA dropping is normal with rain and normal degradation. TA dropping is normal with weekly acid additions.
What's abnormal is the CH rising 300-400%. Do you use calhypo for any reason? If you're not adding CH, it's coming from your plaster and indicative of a larger problem.

 

[RPSalty]

Humbly I bow and shake my head. I swapped the test cylinders. After a ride up to P-A-P, their results were close to my usual results. When I got home I tested again, and as soon as I got the kit out, I realized my mistake.
Their CYA was 90, we never agree on that.
Please moderator, feel free to delete this thread.
Ugh

 

[reggiehammond]

No worries - I did my TA test today with a 10ml sample. Every drop was an instant flash to red. After 2 drops I thought what the heck and noticed my mistake.

 

[jesse-99]

@RPSalty Just curious what you mean by you swapped the test cylinders? Are you saying once you replaced your 25ml test cylinder with a different one your CH dropped back to normal? (confused, sorry if I'm not understanding what happened)

 

[Newdude]

I called the local P-A-P, all their pools samples are indicating low TA. Their data shows recent rain is acidic.

Rain has a Ph of about 5, so.

If your poolstore is anything like mine, they don't know that. One would think that the pool store would know about something that they've dealt with for decades, but they'd be wrong.