pH drifting up

Jump to latest Follow Reply
T

twilson

0
Sep 4, 2009
11
This year, I made the switch from tri/dichlor to liquid chlorine, in both my pool and spa, and have been rewarded with constant CYA levels, which is very pleasing. However, I have been having to deal with a new problem, especially in my spa: pH drifting upward. I have a 355 gal spa, and every time I use the jets, the aeration causes my pH to go up by at least 0.5. Every time I test it, it's up in the 7.9 - 8.0 range or higher. I put in acid to lower it back down to 7.3 or 7.4, but another use with the jets and it's too high again. I try to keep TA around 130 - 150, which is supposed to buffer against the pH swings, but it doesn't seem to be doing much good. And then, every time I lower pH with acid, I'm also lowering TA, and so I have to add baking soda to counteract that. Before, all I had to use was dichlor, which also lowered pH, counteracting the aeration somewhat, and only occasionally had to add acid -- and hardly ever added baking soda. (CH and CYA in my spa are 130 and 35, respectively, FYI.) Things were more convenient before.

Similarly, in the pool, though not as bad. Since the switch, which coincided with a drain and refill, I've been having to add about 3-4 gal of muriatic acid (14.5%) a month, with the requisite baking soda to keep TA constant. (I've been keeping CYA in the pool around 65 -- we have very sunny summers.)

Does this sound normal? Is it the price to pay to keep CYA constant?
 
You need to let your TA come down. The TA causes your pH to rise. A level more around 90ppm would probably be better, maybe even lower.
 
If you are using Wal-Mart or some other off-brand of bleach try switching to chlorox. I had the same problem when using the Wal-Mart brand and when I switched the pH quit rising. Sometimes a batch of bleach will contain an excess of caustic that will cause the pH to increase.
 
OK, I'll bring the TA in the spa down to the 60 - 80 range and see if that fixes the problem, thanks. How about the second part of my question, in relation to the pool: "Since the switch [to liquid chlorine], which coincided with a drain and refill, I've been having to add about 3-4 gal of muriatic acid (14.5%) a month, with the requisite baking soda to keep TA constant.... Does this sound normal? Is it the price to pay to keep CYA constant?" I've kept TA in the pool around 80. The pool doesn't have any water features, although the PV3 system sometimes creates some bubbling on the surface from those nozzles that are on steps near the wall.
 
twilson said:
OK, I'll bring the TA in the spa down to the 60 - 80 range and see if that fixes the problem, thanks. How about the second part of my question, in relation to the pool: "Since the switch [to liquid chlorine], which coincided with a drain and refill, I've been having to add about 3-4 gal of muriatic acid (14.5%) a month, with the requisite baking soda to keep TA constant.... Does this sound normal? Is it the price to pay to keep CYA constant?" I've kept TA in the pool around 80. The pool doesn't have any water features, although the PV3 system sometimes creates some bubbling on the surface from those nozzles that are on steps near the wall.
Click to expand...
Why mix base and acid? They just cancel each other. My pool has a spa that overflows into the pool, so pH is constantly rising. I use a lot of acid. But I've finally got TA down to 80, and it seems to hold there longer. Hasn't changed in 4 days now. If i were you, I'd add acid as needed to keep pH in check and not worry about TA unless it got down to below 70.
 
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