Accidentally added pH Up instead of down.

[chem geek]

It doesn't work the way you think. Yes, it takes more acid to lower the pH when borates are present, but it also has the pH rise more slowly as a result. So the amount of acid that needs to be added over time is the same. You just need to add it less frequently.

It is the lower TA and the higher pH target that will result in less acid addition over time. The borates just have the rate slow down so that you add acid less frequently.

 

[christianday]

Deleting this post because I'd forgot that I added MA. Oy.

 

[christianday]

I deleted my last post because I forgot I'd added MA.

So I added 15oz MA then kept it filter only for an hour then swim jets for three hours. The pH went back up to 7.7 and the TA stayed at 60. Not sure why I cannot seem to move the TA at all but I'll keep trying.

EDITING since the image isn't showing right (and it's still not)

 

[chem geek]

15 ounces of full-strength MA in 10,000 gallons would only lower the TA by 5.9 ppm while half-strength (which is what I thought you were using because you didn't like the fumes) would be only half that or 2.6 ppm. To move the TA down by 10 ppm in a 10,000 gallon pool takes 25-1/2 fluid ounces of full-strength or 52 fluid ounces of half-strength MA.

 

[christianday]

Chem Geek: nope. I stuck with the 31.5. I added 15oz of 31.5 MA to bring it from 7.7 to 7.2. I also included the TA 60 to 50 and the pool calculator didn't tell me to put 25 1/2 oz of 31.5. See the screen cap:



Now, when I change the 60 TA for the NOW field to 70, the number only goes from 15oz MA in the area for pH to 17oz. Could the calculator be off somewhat? Either way, the only way to see how much MA to add to lower TA seems to be to look in the pH area above it in the calculator so I have been using the two in conjunction.

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p.s. it bears mentioning that I've done a total of 30oz of MA today in two separate doses of 15oz. The first 15oz didn't move the TA at all from 60. I'm aerating now so I'll be testing pH and TA again soon or possibly tomorrow when it's light out but I'm wondering if it will have even moved from 60.

 

[christianday]

I thought I wasn't supposed to go lower than 7.2, so I keep adding the MA that brings me from wherever the aeration brought me up to (usually between 7.6 and 7.8) back to 7.2 and start over again but it's taking FOREVER.

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Also, when I change TA NOW/TARGET to 100/100, going from 7.7 to 7.2 pH requires 23oz 31.5 MA rather than 15oz. This is so confusing.

 

[chem geek]

You are using PoolMath to add a quantity of MA to go down to a specific pH so it will be limited in how much TA is lowered each time. If you want to make this go faster, you can add more and the pH will go down lower, but not by too much. Alternatively, you can add acid whenever you see the pH go from 7.2 to 7.4 and not wait until 7.6 or 7.8. Either approach will make it go faster.

The reason that more acid is needed if you put in a higher TA number is that it takes more acid to lower the pH when the TA is higher. That is normal and the way this works.

Since adding 7 cups of MA at a TA of 60 ppm will only lower the pH from 7.6 to 7.0, why don't you just add that much MA at a time since that will lower the TA by 10 ppm at a time. So if you want to get to 50 ppm TA, add 7 cups of MA. You are almost there.

 

[christianday]

Awesome. I appreciate the expertise. I tried measuring out the MA in a cup but it makes the fumes something awful. You would think someone would have come up with a special spout and container or what have you to measure this stuff. I wish they had it in stores in small bottles. I'm going to see if I can order it somewhere that way so it prevents me from overdoing it if I decide to eyeball it.

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And after 17 hours of the filter running without the aeration, neither the TA or the pH have moved at all. Now that's without any aeration. I'm wondering if I should keep the TA at 60 when I put the borates in????

Date	6/22/15
Time	2:33 PM
pH:	7.7
FC:	5
CC:	1
TC:	6
TA:	60
CH:	-
CYA:	-

 

[chem geek]

The half-strength (15-16%) fumes less but some stores charge as much for it as the full-strength which is ridiculous.

You can put the Borates in with the TA at 60 ppm if you want and then see if the pH is stable enough for you. I think it may be OK. You can always lower TA more after the Borates are added, but I don't think that will be necessary.

 

[christianday]

The pool calculator said the borates would lower the ph about .29 so that would bring it to 7.41. However, I'm guessing the aeration will probably stabilize that a little, though maybe not if the borates make aeration take longer. I hope the pH isn't going to be too low once this all distributes. I put enough for a 10k gallon pool to do about 45ppm, just in case it's less than 10k gallons. I need to order borate test strips. I saw those on the tftestkits site so I'm guessing strips are ok for that.

 

[chem geek]

Yes, those strips are the ones to use. Don't worry if the pH ends up being low. You'll be able to aerate to raise it faster if need be or worst case can add a chemical to raise it, but if the pH is that stable then it's doing its job.

 

[christianday]

Yeah, it's been several hours and we've had the jets on with people in the pool and it maybe raised to 7.75 but I can't tell. It's definitely not 7.8 yet so the borates and TA 60 are working good so far. LOVING the way the borates feel in the water.

 

[chem geek]

The nice thing with borates is that their pH buffering is stronger as the pH gets higher. So carbon dioxide outgassing slows down as the pH rises and the pH buffering from borates gets stronger so if the pH is around 7.8 don't fight it and if it gets higher then you can lower it but probably not below 7.6. That will minimize how much acid you need to add and over time the TA will drop further and that will slow down the rate of pH rise even more. Glad it's working out for you so far.

 

[chiefwej]

My issue is that since I borated the TA is now creeping back up and it seems difficult to get it back down.

 

[chem geek]

The TA is probably climbing due to evaporation and refill. The borates won't change that. You lower TA by adding acid and it takes the same amount of acid to lower TA with or without borates. The only difference is that when acid is added the pH won't lower as much but you can still add acid and if you need the pH back up you can aerate.

 

[christianday]

I am ready to throw my hands up in the air. The borates haven't helped at all:

THEN:

Date	6/22/15
Time	2:33 PM
pH:	7.7
FC:	5
CC:	1
TC:	6
TA:	60
CH:	350
CYA:	65

NOW (I waited 8 days to test again):

Date	6/30/15
Time	3:09 PM
pH:	8.2
FC:	5
CC:	0
TC:	5
TA:	150
CH:	450
CYA:	65

So, the HIGHEST my TA ever was before at its worst was 140 and now it's at 150. And the magenta in the pH testing water is so vibrant, that my guess is that the pH is WAY over 8.2. I do not have the borate strips but I carefully measured enough to make it 50ppm so even with the adjustment for water gallon variation, I'm sure there's enough to stabilize this more.

These swim jets must be the most powerful thing on earth to wrench the TA up to that point and the pH too. I'm not even sure where to begin and with the borates in there, now I worry I won't ever be able to get the TA or the pH down again.

 

[chem geek]

Aeration in terms of outgassing does not raise the TA level. Now to the extent that the swim jets are causing more evaporation and that you are refilling with water with TA, then as I wrote the borates aren't going to help with that. With evaporation and refill increasing the TA level (and probably the CH level as well) you will always be adding acid to lower it. You would have to cut out most of your evaporation by using a pool cover or turning off your swim jets to prevent that.

What is the TA and CH of your tap water. Your CH rose which would be consistent with evaporation and refill though it's a pretty big increase in just one week, but your TA rise is more than one would expect.

As for your TA and pH, you can absolutely positively lower them just as you did before. The borates just mean it takes more acid to lower the pH but you must have had a lot of CO₂ outgassing to get the pH to rise after the borates. Adding acid to lower the pH will also lower the TA. You should NOT try and compare TA levels at different pH levels -- the TA will be higher at higher pH, but when you add acid then both will drop down. So just add acid to lower both now.

According to the New Orleans Water Quality Report, "In 2013, the average total hardness in tap water was 163 mg/L on the East Bank, and 114 mg/L on the West Bank." That is hard water, but not extraordinary. I doubt the TA is extremely high, but test it anyway to see. They refer to adding lime for corrosion control so the pH, TA, and CH may indeed be on the high side for your fill water. Again, test it to see. If it's high, then you need to be able to control evaporation and refill or else you'll always be fighting increasing pH, TA, and CH.

 

[christianday]

But it seems like the pH and TA are spiking worse since adding the borates. How is this possible? I'm ready to just have someone send a truck of distilled water and start from zero.

My pool builder said the swim jets are like ten water features. I mean, if just pointing out those little side jets the filter uses up at the surface raises pH, these swim jets must be something ungodly. But they didn't even spike it this bad until I added the boric acid. Now I'd have to empty the whole pool just to get rid of it all. This is so discouraging. At this rate, I'm going to have to add two gallons of MA a week.

 

[christianday]

And now the pH is as magenta as it was at its worst, so the half gallon of MA did absolutely nothing.

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(and that's with the swim jets off all night.)

 

[chem geek]

So if the swim jets are off then everything is fine and reasonably stable with pH but if the swim jets are on then it is very bad, correct? And that the rise in pH seems faster with the borates added? So the borates do add additional pH buffering, but they also reduce the surface tension of the water. So maybe this latter effect with your swim jets is causing more evaporation and therefore refill with water high in TA. So maybe the borates did make that worse though this would be the first time we've seen that happen -- but your swim jet situation is unusual.

However, something doesn't sound right if your having the swim jets be off at night still had the pH rise a lot. Are you taking a water sample about a foot below the surface of the water?

Also, if your FC level is high (especially higher than 10 ppm) then that will make the pH test read higher than it actually is. It will be a very purple color. However, it seemed like your FC was in the 5 ppm range, but if you aren't using a proper test kit then the pH can be affected at lower FC levels. Are you using either the TFTestkits TF-100 or the Taylor K-2006 (I think I remember you saying you bought a TF-100 in another thread)? The Taylor handbook talks about this FC interfering with the pH test, but they have special chlorine neutralizers that are net pH neutral while some other test kits do not.

FALSE READINGS: high levels of chlorine (usually > 10 ppm) will quickly and completely convert phenol red into another pH indicator (chlorphenol red). This new indicator is a dark purple when the water's pH is above 6.6. Unfortunately, some pool operators mistake the purple color for dark red and think the pool water is very alkaline and wrongly add acid to the pool.

When a sanitizer level is not extreme, only some of the phenol red may convert to chlorphenol red. However, purple + orange (for example, pH 7.4) = red. This error is more subtle as no purple color is observed and the operator does not suspect that a false high pH reading has been produced. Some operators neutralize the sanitizer first by adding a drop of chlorine neutralizer (i.e. sodium thiosulfate). However, thiosulfate solutions have a high pH and, if heavily used, may cause a false higher sample pH.

and in this link:

Sanitizer levels > approx. 10 ppm may cause a blue-purple color resulting in false high readings. Wait for sanitizer level to decrease to normal levels and retest to assure an accurate reading.

One way to measure the pH of water that is high in FC or when using an inferior test kit is to dilute it with distilled or deionized (NOT tap) water.