PH readings fluctuate

Jump to latest Follow Reply
J

jkbk223

Member
Jul 11, 2009
15
Flower Mound, Tx
For the first time in 8 years, my pool PH is varying wildly. Usually in Texas in August, the PH gradually goes up and I add acid about once a week. Now, the PH will read 7.7 one day and 6.9 the next day. I retake it in a different part of the pool, and it reads 7.9.
I have to take it several times and finally decide based on several different reading whether to add acid or not.
I have two testing kits and they both seem to read the same.
Is there a reason that the PH could go down to 6.9 overnight?
Our pool is 20,000 gallons, temp. 86, Chlorine 6 (I use bleach), Total Alk 60, Calcium 300, CYA 50, plaster pool.
Thanks,
Barb
 
JesseSchmidt said:
Are you testing after the pump has been running for a while? How old is the pool? I have read that plaster requires acid when it's new but have no experience as my pool is vinyl.
Click to expand...

After 8 years, plaster shouldn't really be affecting pH much any more - and if it were, it would be pushing it up, not allowing it to fluctuate.

The other question is extremely important jkbk - are you testing after the pump has been running for a while?
Also, what do your returns look like - I'm wondering if maybe there are dead spots in the pool.
Finally - what happens when you test in the same exact place, same time, every day (assuming the pump has been on for a while)? Are you still getting fluctuations?

TA is 60, I wouldn't think a TA that is too low could be causing a problem, but you could also try using PoolMath to raise TA to 80 and see if it stabilizes.
 
Test kit is new. I do test in the same spot with the same weird results but now I test 3 times around the pool. 1 will be low, 2 will be high�� I will bring up TA and see if it helps. The pump runs at least 3 hours before testing. Our pool is 16 years old... Original plaster.
 
It's fascinating that your pH fluctuates that heavily.

I'm back to either:

1. The returns are misaimed, creating "dead" spots where the chemicals aren't mixing in.
2. (More Unlikely) - The TA is too low for your particular situation, causing pH flux.

Honestly, wait for an expert to chime in, no worries! We'll help you get it figured out, but you unfortunately have an "interesting" situation. :)
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply