Question about Total Alkalinity

umpalumpajay · Mar 25, 2015

I mostly understand the relationship between Ph and TA and it seems like the majority of people are constantly trying to lower both levels and keep them balanced - at least in southern California. I have a 3 month old pool so im knocking down Ph to 7.4/7.5 pretty much every 6 days as it climbs to 7.9ish. Got my TA down from 100 to 70 with the method suggested here with no problem. now for my question, does TA typically follow the same cycle i've noticed with Ph? it seems more stable and rises slower, but now its down to 60 because im knocking down Ph so often. im worried this trend will continue and TA will drop out of the low end of the suggested range - i could just be splitting hairs - but does TA typically rise at the same level as Ph or am i just looking at the numbers too hard? i read not to focus on TA just to get a number...but i like numbers! hahaha! also, i have a small overflow waterfall on my spa to pool, should i minimize that to decrease aeration and slow ph rise?

Ph 7.5
FC 4
CC 0
CYA 60
TA 60
CH 200
Salt 3400

jblizzle · Mar 25, 2015

TA does not typically rise with the pH.

As the TA drops, and your pool get older, the pH should stop rising as fast. The aeration from the waterfall and the SWG are certainly causing the pH to rise faster than it would without them.

Have you tested your tap water? If you are having to top off water, if that water is high TA and pH, that can make keeping them down even harder.

Can you add CA to your location in your profile as I am sure many have no idea where West Hills is. Thanks

JasonLion · Mar 25, 2015

In addition to what jblizzle already said, freshly applied plaster will raise PH, TA, and CH levels for roughly the first year.

umpalumpajay · Mar 25, 2015

Added CA to profile

Well, what, other than fill water, what changes TA? I've seen a ton on how to adjust it and the effect of high or low levels on ph, but what causes TA to change? Just fill water? Been meaning to test tap water for a base line...i'll get on that tomorrow.

JasonLion · Mar 25, 2015

The most common chemicals which raise TA are baking soda and soda ash. Baking soda raises TA a lot. Soda ash mostly raises PH, but also raises TA a bit. Several other chemicals will also raise TA, though not as their primary effect, and all that much. For example borax and cyanuric acid will both raise TA just a little bit. TA increases can also come from fill water and plaster curing. Any acid will lower TA, though not nearly as quickly as it lowers PH.

umpalumpajay · Mar 25, 2015

JasonLion said:
The most common chemicals which raise TA are baking soda and soda ash. Baking soda raises TA a lot. Soda ash mostly raises PH, but also raises TA a bit. Several other chemicals will also raise TA, though not as their primary effect, and all that much. For example borax and cyanuric acid will both raise TA just a little bit. TA increases can also come from fill water and plaster curing. Any acid will lower TA, though not nearly as quickly as it lowers PH.

Sorry Jason, i meant NATURALLY. like, is there an OUTSIDE factor that would raise or lower TA...other than fill water? dirt, sunshine, chlorine levels (not natural i know), maybe CYA (getting further away from natural, hahah!)

JasonLion · Mar 25, 2015

In a few areas the blown in dust contains chemicals equivalent to baking soda, but that is quite rate. Otherwise, no, nothing except chemical additions, fill water, and plaster curing is changing the TA. Oh, calcium scaling will lower TA.

umpalumpajay · Mar 25, 2015

exactly what i wanted to know! thanks - im focusing on learning what effects what since some levels directly effect other levels and some chemicals effect more than one level at a time. i got into trouble with dichlor not realizing it was jacking up my CYA, not just chlorine - now im off that stuff and just use bleach. don't want to make the same mistake twice by not realizing what can effect what. THANKS SO MUCH!

Richard320 · Mar 26, 2015

TA comes from the fill water, and it can vary a lot during the year, depending on where the water company is getting the water from -- reservoir or wells. Test your fill water and see what it is from time to time.