A bit confused

[Cal_Newbie]

OK, so it has been a number of days while I have been working the PH down with acid and I am in the range I need to be, 7.0-7.2.

Should not the TA be down also? I inquire because my TA is at 250ppm. I used my Taylor Kit at the 10ml mark, added the drops accordingly to the directions annd it took 10 drops to go from green to red and multiply x 25 = 250ppm.

What gives? Do I need to take it lower still, the PH that is? I realize that below 7.0 there is significant problems on a vinyl..so please direct me as to what to do next. I thought I had this doggy whipped...

Bob-

[chem geek]

Bob,

To lower your TA follow Ben's Lowering Your Alkalinity procedure precisely. You are already at the low pH so you need to aerate your water in any way that you can -- point jets upwards, run waterfalls or other features that would aerate the water, put in a recirculation pump and hose that splashes into the water, get an air compressor and put a nozzle at the end of the hose that creates tiny bubbles and put this into the deep end of the pool, have a bunch of kids (or fun adults!) over splashing in the pool, etc.

As you aerate, the pH will rise so you'll need to add acid to keep it in the 7.0 to 7.2 range. After a while of doing this, measure the TA level and when it gets to where you want it (probably under 100 ppm), then you stop adding the acid and just let the pH go up to where you want it (probably around 7.5).

Richard

[Cal_Newbie]

Richard,

So even where my TA is at this time, I can go ahead and aerate? That I can handle. How often shall I test the water PH?

Thank You,

Bob-

[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-