Cant seem to raise TA or PH

[drbob101]

Thank you for the suggestions.

So you think I should add the soda ash now? Is it best to do that with the filter in a ciruclate mode as I have it now and is this best usually? I do not have a circulate mode filter valve so I have been adding borax in the past through the skimmer directly. I could add the circulate valve if it is better to do it this way or just take my filter element out as it is now and run it. That becomes cumbersome though.

I think I will turn off the filter and let the borax settle and vacuum as Carl suggested. We had some rain yesterday and the pool is a tad high anyway.

Thank you

[PoolDoc]

The mods asked me to take a look at this. I can offer two guesses.

A. Guess #1: It is from your liner. (I don't think this one is correct, but it's simpler than #2.)

Liners vary A LOT in quality, durability, and ink stability (they are PRINTED). I've tried several times to discover a way to distinguish between liners, and haven't found one. Flexible PVC -- such as liners are made off -- is not a 'standard' material. Rather, it's a blend of hard PVC, any one of a number of 'plasticizer' compounds, plus fillers and so forth. In other words, you can think of liner material as more like "soup of the day" rather than USDA prime beef. One is somewhat standardized, the other is not.

The point of all this is that liner reactions to chemicals is unpredictable, and varies not just from one mfg to another, but from liner material lot to liner material lot (each lot is a slightly different "soup of the day".)

I realize that this is not a very satisfying response, but I'm sharing with you what I know I don't know . . . and what I know other people don't know, either.



B.Guess #2: . . . take a deep breath. This one is complicated. I will walk through it timeline wise, to keep it as simple as possible.

1. You got brown uniform stains on your white goods, from a combination of iron (doesn't take much) in your fill water and high-ish pH in your pool.

2. Your pH got low -- not "balanced" (6.8 is as low as your kit or strip goes meaning your REAL pH was 6.8 OR lower, not that it was 6.8) and (possibly) you added a HEDP based stain remover, resulting in the iron going BACK into your pool water. BUT . . .

3. You have a heater, and the low pH grabbed some copper from your heater and put IT into the pool water

OR

3. You used some copper algicide (or 'mineral' sanitizer, or some other copper based product) in your pool.


4. Meanwhile, you've been using calcium hypochlorite to sanitize (granules in a sock) raising your chlorine but ALSO your calcium and your alkalinity.

5. And, you may have been listening to pool store advice (S. O. P.) to raise your calcium to "balanced" levels.

6. All these resulted in a high calcium, high actual carbonates (can't explain this now) AND low pH, together with dissolved iron and copper in the water.

7. You started adding borax, and your pool turned milky. This happened because you had too much calcium and "carbonics" (my word -- sorta = alkalinity + dissolved CO2) present. When you raised the pH, you started precipitating calcium carbonate, iron hydroxide or iron carbonate AND copper carbonate . . . which is robin's egg blue. Ironically, something very like this process is used in water treatment and is called "Lime softening". (To soften means, in water treatment, to reduce calcium). Under certain circumstances (like using borax, instead of lime) you can lower BOTH calcium and "TA", while raising the pH.

8. The precipitated calcium carbonates adsorbed the iron (not much, fortunately) and the copper (a lot, apparently) turning the backwash blue.

So . . . the question is, have you added copper, or do you have a heater? If the answer to either is yes, odds are that my Guess #2 is right.

If so,you need to

• filter a lot,
• chlorinate with bleach,
• keep your filter backwashed,
• NOT remove the borax,
• and start adding acid AFTER your pool is clear and AFTER your filter stops removing cloudy junk. (You WANT to remove that excess copper and iron!)

Meanwhile, ignore everything except your chlorine and your pH, till you get to 7.6 or so.

Then repost test results.

There. I've told you all I don't know about this.

Ben
"PoolDoc"

[drbob101]

Thank you so much for chiming in Ben!

I do have a heater and have not put anything in the pool except bleach and chlorine granules since opening 3 weeks ago. Shortly after opening with just the above and a clear pool, I started seeing the brown stains, picture enclosed.

I noticed pH was way low and TA was 50 and added two boxes of Borax and pH didn't budge.At that time I took a sample to Leslie's and bought their TA up stuff. Added 10 lbs of that and nothing changed.

I then posted here and the rest is on here. I will keep filtering and leave the borax.



These are the steps before agging the additional borax.

[drbob101]

The pool is clear after two filter breakdowns and washes.

ph is 8.4 and TA is 50 and the steps etc look like the pictures above.

Free chlorine is >.5ppm, cya is 25.

The liner looks fine also so the blue was most likely a precipiate as per Ben's guess #2, in my opinion. That precipitate that appeared as milky really gums up the filter for future reference.

Please advise what are best steps now to get ph and TA in line and then address the brown stains.

I see Ben advises adding acid now. How much and what kind?

Thank you all for the help
Bob

[Watermom]

In a 20,000 gallon pool, it will take approximately 16 oz. ( a pint) of muriatic acid to drop the pH by 0.2. But, we have learned not to try to adjust something all in one dose, right? So, we want to do this gradually. I think I would add 2 pints. That should take you down to 7.8 but lets see what it does.

Muriatic acid is nasty stuff and you need to be careful with it. Pour it slowly and carefully in front of a return jet. Be careful not to splash it on yourself or on the liner. Try to stay upwind of the fumes and it is best to wear gloves and eye protection. Keep the pump running to let it circulate.

This is also going to drop your alk. So, you're going to need to add some baking soda to raise it. A good range for alk is 80-120.

You also need to add some bleach. With a cya of 25, you want to keep the cl between 2-5 all the time.

What order to do these things? I would add some bleach first. Actually it would be ok to add a couple of lbs. of baking soda at the same time as the bleach. After circulating for a few hours, then add the acid. Then, wait 3 or 4 hours and retest and then go from there.

EDIT -- Just reread your post. Did you mean that your chlorine was >5ppm instead of >.5ppm by any chance? If that is the case, you don't need to add any bleach right now.

[drbob101]

yes...chlorine is >5ppm so no chlorine needed at this time. I will get some baking soda and acid in the morning and proceed slowly with it.

Thank you

[Watermom]

Sounds like a plan. Let us know how it goes and what your numbers are after the additions.