View Full Version : Method of Lowering Total Alkalinity without hardly affecting PH that I found
goldslinger
08-04-2011, 04:01 PM
Hello, All.
I am far from recommending this method. I am mainly posting it to get some Other opinions from it. It worked really well for Me; I couldn't believe how well it worked.
My alkalinity was 190, and My PH was 7.2
The method I found (online in a couple of places) said turn off the pump, let the water currents settle fully; go to the deep end (if You have One) and SLOWLY pour about 1/4 cup of CYA in one spot. Do this in 3 or more spots. Do this away from the sides of the pool. If You have an above pool with no deep end, then just pour more columns of smaller amounts. Wait for 30 minutes or so, then turn the pump back on.
What this does is make vertical columns of highly acidic water that burns the Alkaloids out of the water.
What it did for Me was with One treatment, got My TA down to 100, and the PH dropped to 6.9 - 7. this was with about 1 1/2 cup of CYA.
Has anyone else tried this?
Gary
Watermom
08-04-2011, 04:11 PM
We do NOT recommend this method of lowering alk. Here is the method that we do recommend.
Lowering Alkalinity Step-by-Step (http://poolsolutions.com/gd/lowering-swimming-pool-alkalinity-step-by-step.html)
Using Muriatic Acid Safely (http://www.poolforum.com/pf2/showthread.php?13111-Using-Muriatic-Acid-to-Safely-Lower-Your-Pool-s-pH.html)
waterbear
08-04-2011, 04:41 PM
My alkalinity was 190, and My PH was 7.2
The method I found (online in a couple of places) said turn off the pump, let the water currents settle fully; go to the deep end (if You have One) and SLOWLY pour about 1/4 cup of CYA in one spot. Do this in 3 or more spots. Do this away from the sides of the pool. If You have an above pool with no deep end, then just pour more columns of smaller amounts. Wait for 30 minutes or so, then turn the pump back on.
You mean muriatic acid NOT CYA!!!!!!! Adding CYA will INCREASE TA!
What this does is make vertical columns of highly acidic water that burns the Alkaloids out of the water.
The acid column myth (http://www.poolhelp.com/handouts/oB_Acid%20Column%20Myth%20Handout.pdf) refuses to die even though it has been thoroughly debunked (http://jspsi.poolhelp.com/ARTICLES/JSPSI_V1N2_pp16-30.pdf)!
What it did for Me was with One treatment, got My TA down to 100, and the PH dropped to 6.9 - 7. this was with about 1 1/2 cup of CYA.
NO, you ended up with a final pH of 6.9 AFTER CO2 outgassed. If you aerate the water you can get your pH up the rest of the way. You had local pockets of very low pH that can and will damage pool surfaces.
Has anyone else tried this?
This is how the uninformed lower TA...they belive that 'slugging' acid lowers TA while 'walking' acid lowers pH because someone thought it worked (who did not have a clue about chemistry) and it became a TEKTAT--Things Everyone Knows That Aren't True (Credit to Ben for TEKTATt!) and this myth just refuses to die. However, nothing could be further from the truth...Adding acid lowers both pH AND TA. However, it takes a lot less acid to lower pH than it does to lower TA and if you add enough all at once to lower the TA by the diesired amount the pH drops dangerously low in most cases. Outgassing of CO2 bring the pH back up without raising TA.
Finally, If you added CYA instead of muriatic acid (or dry acid) then you would be raising TA and CYA so you better check on what you actually did!!! Cyanurate ions are one of the constituents of unadjusted TA and to get an an adjusted TA (which is assumed to be just bicarbonate) you subtract approx. 1/3 of the CYA reading from the measured TA. However, if there are borates or phosphates present this changes since they add to the TA also.
chem geek
08-05-2011, 03:02 AM
What are you using for testing the TA? Are you using a Taylor K-2006 test kit? Did you turn on the pump and remix your water before measuring the TA again? Did you mean Muriatic Acid instead of CYA? Did you mean 1-1/2 gallons instead of 1-1/2 cups which would hardly be able to be poured in multiple places into columns?
To actually lower the TA from 190 ppm to 100 ppm in 24,000 gallons would take about 4-1/3 gallons of full-strength Muriatic Acid (31.45% Hydrochloric Acid) and it would not matter how you added it, the TA would drop by the same amount. The difference would be in what happens to the pH and in damaging pool surfaces.
You could very well have added 1-1/2 gallons of Muriatic Acid and if you added enough in one place with the pump off then the TA in that place can certainly drop a lot, even to 100 ppm, but that is not the same thing as having the TA drop everywhere in the pool by that amount. Measure the TA again after turning on the pump and thoroughly mixing the water. 1-1/2 gallons of acid would lower the TA from 190 to about 160 ppm in 24,000 gallons.
CarlD
08-11-2011, 02:45 PM
This is nothing more than the discredited "Column" method of T/A lowering.
Frankly, I find the method and results difficult to accept, and chem_geek and waterbear are two of our best on T/A chemistry.
Are you sure of your chemicals and how you ran your tests? When pH drops, TA does as well, but a .3 drop shouldn't be enough to resolve a TA difference of 190 down to 100.
Carl