Confused about alkalinity range


May 29, 2020
Prosper, TX
Hi All,

Apologies for asking this question in maybe a slightly different way than many other posts. I’ve read pool school, but am trying to get clarification on the difference between the alkalinity range that’s noted in the tf-100 kit vs the pool math app. My results from the tf-100 kit says 80. I wiped the tip of the dropper. The card says best results between 100 and 120. The pool math app says ideal is 60 to 80. I know the exact number isn’t as important as managing the pH, but conceptually, which value or range should I follow? Does the pool math app and range assume some kind of conversion calculation based on CYA?

Thank you!


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Let's really confuse, in reality, any TA of 50 or more.
The ranges in Recommended Levels are built such that you do not need to bother with understanding CSI, if you can stay in all those ranges.
The TF100 information comes from Taylor. Scratch it out or blot it out with a magic marker.

As you have a plaster pool, if you cannot stay in the ranges of pH, TA, and CH, you then must understand CSI. And manage that value to a range of preferably between -0.3 and 0.3.
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May 29, 2020
Prosper, TX
Gotcha....thank you for the quick response (and the help earlier today). Following the pool math app numbers makes sense...just wanted to confirm. And agree about CSI. I’ve been tracking and getting familiar with that metric in addition to the other key numbers.

This has been really helpful, along with reading all of the other forum posts. Apologies for probably the duplicate questions, but thank you so much for responding promptly.

have a good evening,


TFP Expert
LifeTime Supporter
Jul 21, 2011
Eastern Ohio
Let’s confess even more,
The goals were built trying to get people to aim for a lower TA level. Last year we did an audit of over 15,000 test results volunteered from PoolMath and found the average TA of users was around 90-100’ish. Additionally the average pH was around 7.5 if my memory served me correct. It was clear looking at things people were content actively aiming for a low pH and a high TA.......and was using a fair amount of acid to do so.

When we altered the numbers we altered them wanting users to allow their pH to drift upwards. We want users to aim for a lower TA. The amount of acid you’ll save is likely going to be rather noticeable. That said, we also don’t want users to go hog wild trying to hit a number, even though we know some have. Find a happy spot where your pH isn't drifting all over the place. Find a happy spot where you’re not adding acid all the time, and enjoy your pool.