Questions about Boric Acid

hawkmoon7

Well-known member
Nov 27, 2020
56
Florida
After reading up on Boric Acid on TFP, I think it may be right for me. I attempted to use the Pool Math calculator but ran into some questions. First, it lists "Borax (20 mule)" as the ingredient. Is this the same as boric acid?

Second, It says if I add 30 pounds, it will raise Borates by 24. (I think that's a good start). But it also says it will raise PH by 3.1 and TA by 56? How do I keep these numbers in check when adding the boric acid?
 

DorsalSpine

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Jul 8, 2013
863
Columbus, Ohio
20 Mule team Borax contains boric acid. As you noted it will also change your PH and TA. Use Pool math to figure out how to counteract that. The other approach is to purchase granular boric acid. This doesn't change your PH and TA. I've used both and prefer the boric acid over the Borax. I purchased mine from Duda Energy or Amazon. I don't remember which.
 

hawkmoon7

Well-known member
Nov 27, 2020
56
Florida
That is so helpful. I was going to use the boric acid from DudaDiesel. Now that you say it, I do remember that the TFP guide mentioned that the borax method affected the PH more than adding straight boric acid. I should have selected boric acid as an option in the calc. Thanks for that.
 

AK-

Gold Supporter
May 11, 2021
367
Randolph, NJ
Pool Size
7000
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20 Mule team Borax contains boric acid. As you noted it will also change your PH and TA. Use Pool math to figure out how to counteract that. The other approach is to purchase granular boric acid. This doesn't change your PH and TA. I've used both and prefer the boric acid over the Borax.
Actually 20 Mule Team Borax contains Borates, not Boric Acid. One can use either 20 Mule Team Borax + Muriatic Acid OR Boric Acid to add Borates (Boron).

The Boric Acid way is definitively more convenient than the Borax + MA way, but some people argue it is also more expensive.

I got my Boric Acid from Duda Diesel.

Boric Acid will slightly lower your pH as it is an acid. In my case it was negligible.

Borax will increase your pH and TA, so you need MA to compensate.
 

AK-

Gold Supporter
May 11, 2021
367
Randolph, NJ
Pool Size
7000
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Vinyl
That is so helpful. I was going to use the boric acid from DudaDiesel. Now that you say it, I do remember that the TFP guide mentioned that the borax method affected the PH more than adding straight boric acid. I should have selected boric acid as an option in the calc. Thanks for that.
I guess my reply was a bit late to the party.

Don't do like me... get the granular boric acid... I got the powder.
 

JoyfulNoise

TFP Expert
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May 23, 2015
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As others have said - boric acid and borax (20 Mule Team) are NOT the same chemical.

Use boric acid, not borax. Boric acid is far, far easier.
 
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JamesW

TFP Expert
Mar 2, 2011
28,257
20 Mule team Borax contains boric acid.
Borax is Sodium Tetraborate Decahydrate.

When it is added to water, most of it becomes boric acid.

Na2B4O7·10H2O → 4B(OH)3 + 2Na+ + 3H2O + 2OH-

Borax --> Boric acid + sodium + water + hydroxide.

The hydroxide raises the pH and TA, which is why you need to add muriatic acid.

To avoid issues, just add pure boric acid.

B(OH)3 --> B(OH)3

Boric acid --> Boric acid.
 
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hawkmoon7

Well-known member
Nov 27, 2020
56
Florida
Borax is Sodium Tetraborate Decahydrate.

When it is added to water, most of it becomes boric acid.

Na2B4O7·10H2O → 4B(OH)3 + 2Na+ + 3H2O + 2OH-

Borax --> Boric acid + sodium + water + hydroxide.

The hydroxide raises the pH and TA, which is why you need to add muriatic acid.

To avoid issues, just add pure boric acid.

B(OH)3 --> B(OH)3

Boric acid --> Boric acid.
Thank you very much for the explanation!
 
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Selenap

Well-known member
May 28, 2021
244
Waynesville, NC
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I bought granular boric acid. It cost $108 for 55lbs including shipping. It got my pool up to 40-45 ppm. I need more cause we had rain all last week and overflow took some of my borates with it. 😟I threw it all in there at once and it did absolutely nothing to the TA but did lower my ph just a bit. Just like from 7.8 to 7.6. I had raised it in anticipation for lowering it.
 

JoyfulNoise

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May 23, 2015
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Chemicals are in short supply and very expensive with shipping also being a major issue. You want to just use 20 Mule Team borax to get you the rest of the way there. You’ll need to use MA to offset the pH rise.
 
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ArsenalFan

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Jan 29, 2021
48
Brea, CA
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Actually 20 Mule Team Borax contains Borates, not Boric Acid. One can use either 20 Mule Team Borax + Muriatic Acid OR Boric Acid to add Borates (Boron).

The Boric Acid way is definitively more convenient than the Borax + MA way, but some people argue it is also more expensive.

I got my Boric Acid from Duda Diesel.

Boric Acid will slightly lower your pH as it is an acid. In my case it was negligible.

Borax will increase your pH and TA, so you need MA to compensate.
I also got mine from Duda and from my experience the easiest to dissolve in the pool
 

ArsenalFan

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Jan 29, 2021
48
Brea, CA
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My issue now and I only have 25ppm Borate but we seem to be itchy when we get out of the water whereas before with just the SWG we never got itchy.
 

BenB

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Jul 24, 2020
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I never really understood the "it's much easier" argument for boric acid. PoolMath literally tells you how much acid to add and you're already dumping in multiple boxes of something, so the extra couple of minutes to add a gallon of MA seems trivial to me, and it neutralizes the pH and TA rise immediately before anything else bad can happen, while being much cheaper (assuming you can get good acid cheaply).

I'm sticking with the mules :)
 
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