Can’t get/keep ta down

Ajfinny

Member
Jun 4, 2019
12
Dixon, California
No idea why... I add enough acid to lower it, but then the next day or 2 days later it is the same or maybe even higher... like 100 yesterday, waited till today to test again before adding chems, and it is 110 today..... grrrr... go through about 4 gal acid every 2-3 weeks.....
 

JamesW

TFP Expert
Mar 2, 2011
15,509
What's the fill water TA?

Are you adding fresh water daily?

Do you have an autofill?

What are all of the chemistry readings?
 

Ajfinny

Member
Jun 4, 2019
12
Dixon, California
It was a fresh build a year and a half ago... I haven’t tested the full water ta, but I have the auto fill turned off at the moment (leak in the front yard irrigation/sprinklers that it is sourced from). I’m not adding water daily, but every few days in this NorCal heat wave and splash loss...
Yesterday readings attached in pic. CSI is -.06 with these readings, water temp got to 85 yesterday, salt 3500, borates 0 (i admittedly don’t know the borate reading).
I think it is leaching, which is frustrating, cuz I get some scaling and have some small “specs” or “spots” of what I would describe as white scale or “calcium” “spots” that have formed on some steps and other places but not the entire pool surface (pics also attached). I would love to get rid of these...
869B1039-5CFF-4ABB-B7AF-D27B54A27339.png79D628B5-EE97-4CE5-B715-DD004B9F1F8E.jpeg2F80D4DE-5D87-401E-9C3E-A89AEDD71A5D.jpeg
 

JamesW

TFP Expert
Mar 2, 2011
15,509
The white spots and lines look like they might be calcium nodules. Some of the plaster might be delaminating.

You should brush the pool regularly.

A rising TA needs a source of something alkaline. Let's see what the fill water is.
 

Ajfinny

Member
Jun 4, 2019
12
Dixon, California
Calcium nodules sound like an accurate description... any info/educational material I could read about it more? Is brushing the only preventative for it? Advice on removing it? Can I use my pumice stone (I use on the tile) on the plaster to get rid of these “nodules?”

Also, can you shed more light on “plaster delaminating”??? That sounds not so good :(

I can test the fill water after work today.
 

Ajfinny

Member
Jun 4, 2019
12
Dixon, California
I found the tfp info page about nodules and delaminating... thank you. I will try discreet sanding/pumice stoning to try and remove them...
I should also state that I suppose my pool is technically a replaster job since we had an issue with a leak after the original construction and the entire spa was rebuilt and the plaster company ended up demoing out the entire pool plaster and re-doing it....
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
21,226
Laughlin, NV
Do not be so aggressive with the acid. pH below 7.2 can damage equipment, plaster, etc. Definitely will damage your heater and SWCG.
 

JamesW

TFP Expert
Mar 2, 2011
15,509
Your fill water has high TA. With high evaporation and refill, it will raise the pool TA. Probably going to be a continuous process.
 

Ajfinny

Member
Jun 4, 2019
12
Dixon, California
Ok cool. Been running the waterfall to aerate. Baffled by rising TA. Zero full water added in last few days. Pool gets direct sun all day, no cover, shade in the late afternoon and evenings...
We had a pool party yesterday with 12-15 kids, and adults, so lots of aeration, and ran the spa with heater, and today it’s up to 100.... ph is up to 7.3/7.4.... I’ll keep going to 7.6-7.8 then drop it to 7.2 as needed to get TA down to 60-80.... today’s numbers just now:
 

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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
21,226
Laughlin, NV
TA can only rise if you add it to the pool. Either with fill water, baking soda, or soda ash. Or testing error.
 

Ajfinny

Member
Jun 4, 2019
12
Dixon, California
TA can only rise if you add it to the pool. Either with fill water, baking soda, or soda ash. Or testing error.
Or liquid chlorine right? Odd. This is why I’m frustrated. I’m the one doing the tests, so if it was an error, then I’d think I’d get equally wrong results each time I do it, not wrong one way one day and wrong a different way the next day... I don’t know how long it takes for chem levels to “stabilize,” but Maybe I need to wait a day between testing, but seems pool school article on lowering total alkalinity says I can retest after 30 min of chem addition with the pump running... idk.
Thank you all for helping me learn and figure this all out and bearing with me as I make slow progress....
 

Rocket J Squirrel

Bronze Supporter
Jun 7, 2018
463
Alamo, CA
I have been trying to lower my TA for a year, since my pool was resurfaced & refilled. Not yet knowing how to startup myself, I paid guys to do it, who put in too much “Alk Up” or whatever it’s called.

I can’t do it. I understand the recommended process, but it doesn’t work. With the constant pH rise from new plaster, I thought lowering TA with MA would be a breeze. Nope. My TA wants to be 120. Sometimes it seems to drift up to 130, and sometimes I can get it down to 110 temporarily.

Now my pH is finally stable. I give up on the TA. My fill water has 40 TA, but I ain’t gonna drain & fill just for that.