extreme TA drop, is this even possible?

crackers8199

Well-known member
Jun 5, 2014
84
Lake Elsinore, CA
without getting into too much backstory (because it's confusing and i'm stupid for thinking pool store tests were ever valid to begin with): is it even possible for TA to drop from 85 to 22 in a matter of two weeks with just 3 acid additions over that time period?

long story short: i'm just now trying to take over maintenance and control of my pool, been working at it for about a month now. ordering my taylor test kit today (this is another addition to the part about me being stupid and not having just ordered it when i started). i also have a waterguru sense that i bought and installed based on the positive reviews of some here and elsewhere. over the past week i've been using the WG to tell me when to add acid to maintain my ph, i've been taking the water to the pool store multiple times a week early on to test the rest of the chemistry.

first pool store test said my TA was 0. added baking soda and took it back, up to 120. steadily came down over the next few weeks: 98, 92, 85. today was the first time i decided to take the water back to the store and have it checked again, since the WG has been telling me when to add acid. today's pool store TA reading: 22.

now, i did add a bit much acid yesterday...the WG told me my ph was 7.8, so in my trying to bring it down to 7.5 i actually added too much acid and brought it down to 7.3. this is the third time i had added acid over the past two weeks (which was the last pool store test, which again measured TA at 85).

so my question is three fold - main question for this thread is: is it even possible for TA to drop from 85 to 22 just by adding acid to maintain the ph over a two week time period, even if i might have overshot the acid target yesterday by a little?

and second: which kit is the best kit for me to get? i've been struggling to decide / understand the differences between the K-2005 and K-2006 and SALT versions, and want to make sure i get this right for both the amount of money spent and my pool's sake...

and third: should i assume the pool store test is right and add baking soda? or should i do nothing and wait until i get my own kit and test it myself? should i worry that having a low TA for a few days until my kit comes in will cause any issues?

feel free to hammer me with any questions and/or tell me i'm stupid (i already know i should have just started with the test kit lol)
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
31,077
Laughlin, NV
How are you chlorinating?

very doubtful. If your pH is steady in the 7’s, I would not add baking soda.
Order a TF100. From TFTestkits.net.
 

crackers8199

Well-known member
Jun 5, 2014
84
Lake Elsinore, CA
How are you chlorinating?

very doubtful. If your pH is steady in the 7’s, I would not add baking soda.
Order a TF100. From TFTestkits.net.
pentair IC40. it may be close to its last legs but it seems to be still working for now. over the winter it was definitely not working (so i switched to pucks, which i then subsequently extremely overdosed the pool on and skyrocketed the FC level. took the salt cell out and cleaned it again a few weeks ago (second time this year), and now it's on and working again. has to be, because there's chlorine in the pool and i haven't had the floater in in weeks.
 

crackers8199

Well-known member
Jun 5, 2014
84
Lake Elsinore, CA
If your pH is steady in the 7’s, I would not add baking soda.
it's somewhat steady but drifts high (which i guess is to be expected with the SWG). when i installed the WG on saturday, it told me it was 8.1. here are the readings from the WG this week:

saturday: 8.1 (add acid)
sunday: 7.6
monday: 7.7 (add acid, i'm guessing i didn't need to do this here based on other comments i've seen on the forum)
tuesday: 7.5
wednesday: 7.6
thursday: 7.8 (add acid)
this morning: 7.3
 

crackers8199

Well-known member
Jun 5, 2014
84
Lake Elsinore, CA
OK -- I would not make any adjustments based on those data points. They are an indicator, but not all that accurate.
reports from users here seem to indicate the ph readings from the waterguru are pretty much right on, that's why i figured i was safe to use that to keep ph in check until i get a test kit in my hands.
 

crackers8199

Well-known member
Jun 5, 2014
84
Lake Elsinore, CA
Tests you trust are up to you.
I trust the waterguru based on the information I've gotten from people here. The pool store test a little less for the same reason, although their CL and pH numbers matched what the waterguru said yesterday.

Right now my concern is am I ok with that alkalinity until my test kit comes in, if it is in fact that low? That's why I was asking if it was even possible for that kind of drop just from adding acid to adjust the pH...
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
31,077
Laughlin, NV
If your pH rose by 0.3 in a day, your TA is not low. It, in fact, is most likely quite high. Or, you have massive aeration each day or you are adding a base chemical to your pool each day.
 

crackers8199

Well-known member
Jun 5, 2014
84
Lake Elsinore, CA
Do you have automation? Easytouch?
nope, just the variable speed pump on a schedule and the mechanical intermatic timer that flips the SWG on and off every day. planning to upgrade that to digital but haven't gotten that far yet...

the pump runs at higher speeds for 3 hours each day in the early AM, then lower speeds for another 4 hours in the AM and 2 hours in the late evening.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
31,077
Laughlin, NV
OK - so no way to eliminate the spillover for most of the time. That will drive up your pH. So you will just have to deal with that.