A bit confused

[chem geek]

Bob,

I'm not sure what you mean by "even where the TA is at this time" since your TA is definitely too high. You can most definitely aerate. As far as how frequently to check pH, I can't tell you that because it really depends on how effective your aeration is. Just test it after a few hours and if it's not changing very much you can check on it less frequently, but when it goes up measurably (say, from 7.2 to 7.4) you can add acid to bring it back down. I assume you may have an acid demand test to tell you how much acid to add, but I can give you a rough idea BUT it depends on your TA level so as the TA gets lowered it will take less and less acid to bring the pH back down from 7.4 to 7.2. If your pH test reliably tests down to 6.8, then you can use 7.0 as your target or 7.1 which would be in between the 7.0 and 7.2 colors on your test. The point is that this process is more effective at lower pH, but don't worry that being right near 7.0 is going to somehow destroy your vinyl -- it won't. You just don't want it to get much below 7.0, that's all, so using 7.0 or 7.1 as your "target" during this process is fine.

As an example for your 9600 gallon pool, when the TA is at 250 ppm it takes 26 ounces or 3 cups 2 ounces of Muriatic Acid to go from a pH of 7.4 to 7.2 (43 ounces or 5 cups 3 ounces to go from a pH of 7.4 to 7.1).

For comparison, at a TA of 150 ppm it takes 16 ounces or 2 cups to go from a pH of 7.4 to 7.2 (27 ounces or 3 cups 3 ounces to go from a pH of 7.4 to 7.1).

For technical reasons it takes less acid to lower the pH in a higher pH range than in a lower pH range, so trying to get to a much lower pH gets progressively harder -- kind of like pulling on a spring. That's why the amount of acid to get to 7.1 compared to 7.2 seems to be more than one might expect.

Richard

[gonefishin]

Hi there

Just be sure to stick with the procedure that the others are describing. I had to bring my TA down last year and this process does work. But you need to be patient...and you need to follow the instructions. While your going thru the process think of it as if your just chipping away at the TA a little at a time by bringing down the ph...then aerate...measure measure. Bring down the ph...while still aerating...measure measure. Bring down the ph...you get the idea

Just stick with it! it does work.


Are your (bad) Combined Chlorimines gone yet?


stick with it!
dan

[CarlD]

Shoulder surgery? Ouch! That hits me where I live! Three years ago at this time I was recovering from a motorcycle accident where my shoulder was dislocated--very badly. I have NO idea how I avoided surgery other than a very, very astute orthopedist whose prompt actions and un-orthodox casting allowed it to heal naturally. Didn't sleep more than an hour at a time for months, and my wife never knew where she'd find me in the morning--where-ever I could fall asleep next.

The doc sent me to P/T as well and THAT was as important as his actions. 6 months of grueling P/T, but it worked. I always say attack P/T like it's an enemy. I'm not super-agressive, but I saw that the harder I worked, the better my chances of recovery.

Lowering total alkalinity is VERY confusing. Let me try to clear it up.

1) T/A and pH are linked. As pH goes up or down, so does T/A.

2) There are very few ways to move either T/A or pH MORE than the other.

We can raise T/A more than pH by adding baking soda. We can raise pH more than T/A by aerating.

That's it.

3) But we can ONLY raise pH via aeration when pH is 7.2 or less.

4) So we LOWER pH to 7.0-7.2, which pulls T/A down (see 1) again). We don't go lower than 7.0 because below 6.9 vinyl can be damaged. Concrete/Plaster/Gunite is not as sensitive to pH.

5) We then aerate which raises pH WITHOUT raising T/A--it's the ONLY way to do it. (Why does this work? Ask Chem_Geek--he's the BEST at explaining it)

6) We then repeat 4) and 5) again and again until T/A is where we want it.

Once you understand which action does what, it makes a lot more sense. Aeration does NOT lower T/A--that's frequently mis-understood--it's dropping pH to 7.0-7.2 that does it. Aeration raises pH without raising T/A.

[Cal_Newbie]

OK, definitely understanding this stuff and yes, it is difficult to get it down as the pH range gets closer.

I have my return eye pointing virtually straight up and it creates a serious amount of splash, to the point it splashes out all sides of the pool...so that is sufficient.

I had to go out of town and of course, no one followed my directions and so I went from a pH of 7.2 and arrived home to an 8.0.GRRRRRRRRRRRRRRRRRRRR

So back to the beginning and I will get this TA down yet.

Shoulder? 4 tears averaging 4-5mm each, acromium bone removal, socket enlargement and bicep muscle reattachment...fun, fun, fun. Actually rather have surgery again than deal with this flippant TA!!!!

Bob-

[CarlD]

Shoulder? 4 tears averaging 4-5mm each, acromium bone removal, socket enlargement and bicep muscle reattachment...fun, fun, fun. Actually rather have surgery again than deal with this flippant TA!!!!

Bob-

Bob:
Wow! Dealing with lowering T/A should definitely NOT hurt as much as your shoulder! How DID you do that? I crashed a motorcycle--first time since 1978 I had gone down hard. The bike was fixed and trouble free faster than I was--and at a far lower cost, too!

Of course, getting someone to follow directions while you are out of town can be tough...luckily I've never had to SOLVE a problem while away, and I have a fairly good system for having a "helper" care for my pool while I'm away:

Every 2 days dump in 1/2 gallon of bleach. That usually leaves me JUST FINE for up to 2 weeks. The ONLY hitch was I asked my father-in-law to save the gallon jugs as I was refilling them from two carboys--one with 12.5% LC and the other with water, to get me 6% LC.

Naturally he recycled all the empty jugs...into the town's Recycling...

[Cal_Newbie]

Now I have Carl pittying me!!!

Did it xmas eve, middle of the night. I am a pro Firefighter/Medic and had a drunk guy that got pounded well by his friends..nice guys. He was behind a house with a million broken down cars and I had to put him on a backboard due to Mr. Liability and low-and-behold... no way to get him between the cars...way too narrow. So everyone starts to whine and no one wants to do anything but complain, so I grabbed the board and drug his butt up and over about 4 cars. When I got to the other side and started to lower...POP! Niiiiiiiiiiiiiiiiiiiiiice, thank you Santa. Then I garnered a wonderful butt-chewing for performing an unsafe act upon myself...wtf? Lazy crew did not want to lift, ambulance cried and complained and no way out except that.... so I did what every good subordinate does, throw his supervisor under the bus....hey, he could not make up his mind, my firefighter was a on probation so he was worthless, I hate sitting around roasting marsh mellows and took the initiative.

PT is going fine, life sucks after all those good drugs they used for a block wore off. So I have been one arm building my deck and fence and post hole digging... tis the life of Bob.....have 3 boys but will they help dear old dad....ROFLMAO!!!!! Worst part is you cannot sleep, the shoulder just nags, nags, nags like a mother-in-law..then Workers Comp had me wait it out for 3.5 months... but I did have a great surgeon.

OK, back to what is truly my pain.....pH. Mr. pH is down again to 7.0 and TA has dumped to 190...YEAH!!!!

So I keep on turning the water heavily... check the pH and keep it down until my TA gets to what? 150-170ppm?

So I will need to shock the pool when my pH rises back up into the acceptable range and my TA is basically where it is at or a bit lower?? Shocking will involve 2 gallons of bleach to get me into my range for shock. Pheeeeeeeeeew. Think I will go run my 110# jack hammer to alleviate my pool chemistry nightmare...where is my vicoden?

Bob-

[chem geek]

Carl and I disagree a little on the ideal TA, but when using BBB I say to shoot for 80 ppm if you want to avoid pH rise while Carl says 100. I think either is fine and is wholly dependent on the amount of aeration there is in your pool. It also depends on your final target pH -- if it's higher, you get less of a tendency for pH to rise.

So pick whatever target you want, say 100, and just see how it goes. If you find that you are adding more acid than you would like to keep the pH at your target of, say, 7.5, then you can always lower the TA some more or can choose a higher target of 7.7 or so.

And re your shoulder and circumstances -- you're a hero and I'm sorry that fear paralyzed some of your partners, but am mostly sorry that you got hurt. Certainly, making your pool a bigger frustration will lessen your (real) pain.

Richard