I am confused about pH and TA (Total Alkalinity) and was wondering if
someone out there can explain what's going on.
I had to add quite a bit of soda ash to our inground, vinyl-lined,
bromine-sanitized pool this year to get the pH up to an acceptable
reading (around 7.5). After I did that, the TA reading went through
the roof (300, where the suggested reading should be between 80-120.)
I've talked to every pool and pool chemical dealer in my area. Their
answers and suggestions have been like snowflakes: no two are the
I tried adding 1 gal of muriatic acid...this did lower my TA to 270
(still way too high) but also screwed up my pH (now back down to 6.8).
It is even possible to get these two readings back within acceptable
ranges at the same time?
Thanks in advance for any help/advice/info!
I've never had this problem, but this is what I've read. Since most items
that increase pH also raise TA quite a bit, all you can do is try to
concentrate where you put the acid. Suposedly, this lowers TA more than pH.
If you spread the acid evenly around the pool, it lowers pH faster than TA.
When you added the soda ash, did you evenly distribute it or dump it in a
single area. Again, if raising pH was the goal, it should have been evenly
distributed around the pool.
How was the TA when the pH was originally low -- about the correct range? Do
you use baking soda to increase TA?
Finally, do you have any idea what the pH is of the bromine that you use?
For chlorines, each of the three common choices has a different pH (Trichlor
3, Dichlor 6, and Cal Hypo 11.5). If bromine is making things acidic, you
may want to look for a variant that is more basic.
Now, that is strange. How could the means of dispersal have any
effect on the overall result of adding a chemical? Any chance you
would remember where you read/saw that? I'd love to read it myself.
I evenly distributed it.
The TA was essentially perfect (around 100 ppm) before I did anything
to try to raise the pH, which was about 6.8. I have never used
anything at all to raise the TA because I've never wanted to raise
it...until now it has been fine.
I use bromine tabs in a chem feeder...no idea what their effect on
total pH is, but I can find out.
I looked in my two books, but didn't find it there. I've gathered info from
lots of places and I keep a pool chemical sumary sheet for when I need to
adjust things. I believe the TA gets eaten up when you have enough acid to
do it. Just evenly distributing it won't overcome the TA.
Where you get your water tested, do they do a detailed test that tells you
your hardness, TDS, cyanuric acid, metals, and other things? If not, I'd but
some test strips that measure the first two. If either the hardness or TDS
is too high, you may have to drain a lot of water and start again. This
condition is made worse by adding excessive chemicals.
Use a test kit that requires the chlorine to be neutralized for the pH
and TA test. Allow chemicals 3 to 4 days to circulate before making
I've written this before but it's so important I'll repeat it. Inadequate
circulation leaves a huge amount of pool water void of the chemicals
you put in. Timing is very important. Chemicals that don't disperse
properly and evenly can be just as bad as using 2 lbs. of shock in two
days instead of 4 pounds of shock in one day.
Draw water from the bottom of your pool by leaving the vac head
down there. Take a pH reading after three or four days. You will
see the pH slowly rise to the point your high TA and pH makes
At this point bring a sample in to get it analyzed.
I'm not sure what you mean by "neutralized"...would that be the same
as "stabilized"? At any rate, this is a bromine-sanitized pool. I do
wait a few days to take readings.
I always put any treatment in the pool early in the day, so the pump
will run all day.
We have a drain at the bottom of the deep end, and a vacuum plate with
a plug in the skimmer...combined with a little stop valve in the
bottom of the skimmer, this allows the pump to draw all of its water
from the bottom drain only.
Hmm, if I follow you, you're saying that after 3 or 4 days I will see
the effect of my adding the muriatic acid (which lowered the pH) wear
Yeah, I would, but I would expect to get different advice depending on
where I brought the sample. That's the crux of my dilemma, another
way of stating which would be I can't find a dealer/tester in my area
that I have any confidence in. Suggestions ranged from: "get your pH
right and don't worry about the alkalinity..." to "drain the pool and
Thank you for your advice.
I see you don't trust pool dealers because they each give you different
advice. Well, I give you advice and mine doesn't make sense to you
either. You need to see good results first, and then go back and learn
why it worked. You also asked someone to come up with where they
saw it say how to disperse the chemicals, either concentrated in one
small area or evenly dispersed. Forget it, just do it and we'll explain
Those suggestions sound good to me.
I have an in-law who prides herself for not having to shock her pool
because she keeps her sanitizer level real high. The one feeding her
this BS is the same dealer I go to occasionally. He's not a bad guy.
He just finally gave up on her. Her liner went brittle and was replaced
this year after a four week order it and wait. Last I heard she's back
doing the same BS. My in-ground is three times larger than her pool
but she uses three times more chemicals than I do. Mine is sparkling
clear everyday. She has seen it. Does it sink in??? Hell no!
So, if she had your problem I'd tell her to drain the pool. Screw it.
Different dealers have different attitudes caused by the customer.
Your problem could be a small crack in one of the underground lines.
When the pump is off the crack allows water to seep out. When the
pump turns back on it draws the water back in along with small
amounts of soil. This can cause the pH to read low. Maybe the
crack doesn't always seep water out because the crack fills in
sufficiently. How could a crack develop? Freezing is one possibility.
Maybe you added too much calcium thru the skimmer to harden the'
water and the calcium clogged and burned your pipe.
Your problem could be caused by the paint on your patio leaching
into the pool. Or fertilizer or grass clippings, or even a clogged
I have been where you are now. I use baking soda to raise the pH
and I use (I forgot the chemical name, something hydrogen) to raise
the TA without effecting the pH. If I needed to lower the TA I would
use muratic acid (one pint) locally in one small area. I would use
a dry ingredient like Low 'n Slow to lower the pH because that stuff
can be scattered over the surface.
Study up on what TA actually is and what it's make-up is all about
and then you should be able to understand why a concentration of
acid works on the TA and has little effect on the pH.
One more piece of advice before I go. When you first noticed 6.8 pH
and a TA of 100 I'm guessing your pH was actually in range, maybe
7.2 or 7.4. If indeed it was 6.8 that wasn't enough to start tweaking.
You have to decide how to attack a problem by the direction things
are headed. I've seen pool water take almost two weeks to
finally show an accurate result from the chemicals added two weeks
My pool is closed now. I can fertilize my lawn now without having
to worry about nitrogen or potassium entering the water. If I had
a mesh cover instead of a solid cover I'd have some severe problems
I use the reel that the solar cover was attached to roll up the pool
cover. Little by little I'm able to wash both top and bottom of the
cover. When it came time to cover the pool I simply rolled the cover
over it. Dragging a cover over the lawn is not a good idea.
The cleaner the cover the cleaner the water next spring.
I had the same problem. Got only part way to solving it before we sold
the house. Basically I drained some of the water and added new water.
That helped quite a bit.
It's very frustrating and drove me crazy. One of the reasons I refused
to buy a new house with a pool. (It was too small to do more than a
couple of strokes anyway).
Yes, at some point you have too much stuff dissolved in there, and you need
to start over again with relatively pure water. Otherwise you have this
chemical tug-of-war going on that you can never keep stably balanced.
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