Difference between revisions of "Borates in pool" - Further Reading

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[[Category:Swimming Pool Chemicals]]
 
==Why should one use Borates==
 
==Why should one use Borates==
  
−
Adding borates to your pool can improve your experience with your pool, but is completely optional. The key benefit of adding borates to your pool is to help slow pH increase. If you do plan to use borates, wait until everything else is settled down before adding borates, especially [[TA]] and [[PH]]. The only situations where we specifically recommend using borates are for pools with a negative edge or other very large water feature creating huge amounts of aeration and for spas using the dichlor and then bleach method. All that said, borates have proven popular with many pool owners.
+
Adding borates to your pool can improve your experience with your pool, but is completely optional.  
 +
 
 +
The key benefit of adding borates to your pool is to help slow pH increase. If you do plan to use borates, wait until everything else is settled down before adding borates, especially [[TA]] and [[PH]], and you have a good understanding of how your pool chemistry works.  
 +
 
 +
The only situations where we specifically recommend using borates are for pools with a negative edge or other very large water feature creating huge amounts of aeration and for spas using the dichlor and then bleach method.  
 +
 
 +
All that said, borates have proven popular with many pool owners.
  
 
===Benefits of using Borates===
 
===Benefits of using Borates===
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*Silky water feel
 
*Silky water feel
 
*More water sparkle
 
*More water sparkle
 +
 +
[https://www.aquamagazine.com/service/chemistry/article/15352890/the-borate-pool-opening The Borate Pool Opening] in Aqua Magazine discusses how borates can limit pH rise while a pool is closed for the winter. High pH while a pool is closed can cause scaling. For those that find their pools with very high pH at Spring opening borates may benefit with the pool open or closed.
 +
 +
===Borates buffering pH rise===
 +
 +
1÷(1+10^(pKa – pH)) = borate percentage.
 +
 +
1÷(1+10^(9.15 – pH)) X 100 = borate percentage.
 +
 +
pH.....Borate.....Boric Acid.
 +
 +
7.2.....1.1%..........98.9%
 +
 +
7.4.....1.7%..........98.3%
 +
 +
7.6.....2.7%..........97.3%
 +
 +
7.8.....4.3...........95.7%
 +
 +
8.0.....6.6...........93.4%.
 +
 +
As you can see from this chart, most of the borate is in the form of boric acid, which contributes to the total acidity.
 +
 +
Total acidity is the same concept as total alkalinity but total acidity buffers pH rise whereas total alkalinity buffers pH drop.
 +
 +
Borates at 50 ppm provide as much protection from pH rise as 221 ppm of TA provides against pH drop.
  
 
===Downfalls of Borates===
 
===Downfalls of Borates===
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*Concerns about risks to pets
 
*Concerns about risks to pets
 
*Not a magical potion to solve all pool woes
 
*Not a magical potion to solve all pool woes
 +
 +
===How do Borates Affect a SWG?===
 +
Borates can act as a mild algaecide and so people usually see that “boost” in efficiency because borates can make it harder for algae to replicate. Borates is also a strong buffer against high pH changes inside the cell as the pKa is around 9.0 for the boric acid/borate ion buffer system. Keeping the pH in check means that calcium scaling is less likely and thus the cell can run without getting coated with scale. Scale reduces the efficiency of the cell.<ref>https://www.troublefreepool.com/threads/borates-and-swg.194373/post-1713562</ref>
 +
 +
Hydroxide is produced in the cell.
 +
 +
2H2O --> H2 + 2OH-
 +
 +
2 water –> Hydrogen gas + 2 hydroxide.
 +
 +
The hydroxide converts bicarbonate to carbonate.
 +
 +
HCO3- + OH- --> H2O + CO3^2-
 +
 +
Bicarbonate + hydroxide --> water + carbonate.
 +
 +
Then, the carbonate connects to calcium and you get calcium carbonate.
 +
 +
Ca^2+ + CO3^2- --> CaCO3
 +
 +
Calcium + carbonate --> calcium carbonate.
 +
 +
Boric acid protects from pH rise by accepting and binding to the hydroxides produced in the cell due to the production of hydrogen.
 +
 +
B(OH)3 + OH- --> B(OH)4-
 +
 +
Boric acid + hydroxide --> Borate.
 +
 +
So, it's really boric acid and total acidity that provides the protection from pH rise and cell scaling.
  
 
==How to add Borates to your Pool==
 
==How to add Borates to your Pool==
−
We recommend maintaining borates between 30 and 50 ppm. That normally means raising the borate level to around 50 each spring, so that it will still be above 30 come fall.
+
We recommend maintaining borates between 30 and 50 ppm.  
  
−
Before you start on borates, adjust your [[TA]] level toward the low end of the appropriate range for your pool type. See the [https://www.troublefreepool.com/content/134-recommended-levels Recommended Levels chart] for appropriate levels. It is easier, and better, to adjust [[TA]] before adding borates than it will be after.
+
Borates leave the water primarily through splash out and backwashing. <ref>https://www.troublefreepool.com/threads/do-borates-degrade.261349/post-2285195</ref> Borates are also lost when draining the pool during winter closings. Borates do not degrade.
 +
 
 +
That normally means checking and raising the borate level to around 50 each spring at the start of swimming season, so that it will still be above 30 come fall.
 +
 
 +
Before you start on borates, adjust your [[TA]] level toward the low end of the appropriate range for your pool type. See the [https://www.troublefreepool.com/content/134-recommended-levels Recommended Levels chart] for appropriate levels.  
  
 
There are two approaches to adding borates to the pool: boric acid, or a combination of Borax and muriatic acid. Using boric acid is just slightly more expensive, in most cases, and much easier. Borax and muriatic acid takes more effort and handling that much acid is just slightly risky, but saves just a little money if you shop carefully.
 
There are two approaches to adding borates to the pool: boric acid, or a combination of Borax and muriatic acid. Using boric acid is just slightly more expensive, in most cases, and much easier. Borax and muriatic acid takes more effort and handling that much acid is just slightly risky, but saves just a little money if you shop carefully.
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Calculate, using [https://www.troublefreepool.com/content/114-poolmath-pool-calculator PoolMath], how much Boric acid you will need for 50 ppm.  
 
Calculate, using [https://www.troublefreepool.com/content/114-poolmath-pool-calculator PoolMath], how much Boric acid you will need for 50 ppm.  
  
−
Boric acid can be purchased from DudaDiesel and The Chemistry Store. Granular is much easier to work with than powdered. Technical grade is fine.
+
Boric acid can be purchased from [http://www.dudadiesel.com/search.php?query=boric+acid DudaDiesel] and The Chemistry Store. Granular is much easier to work with than powdered. Technical grade is fine.
  
 
Distribute the boric acid across the surface of the pool. Keep the pump running for at least one hour after adding boric acid, and then test the pH and adjust if needed.  
 
Distribute the boric acid across the surface of the pool. Keep the pump running for at least one hour after adding boric acid, and then test the pH and adjust if needed.  
  
 
Boric acid will lower the pH slightly. Usually the pH change is small enough that no further adjustment is required.
 
Boric acid will lower the pH slightly. Usually the pH change is small enough that no further adjustment is required.
 +
 +
Proteam Supreme Plus is Sodium Tetraborate Pentahydrate and will significantly raise your TA while adding borates to the water. We recommend you use Boric Acid, which adds a minimal amount to your total alkalinity.<ref>https://www.troublefreepool.com/threads/proteam-supreme-plus-raised-ta.214268/post-1875423</ref>
 +
 +
===Do Not Use Roach and Ant Killer for Boric Acid===
 +
Roach and Ant killer can contain boric acid and labels may say it is 99% boric acid and 1% inert.  However, they will be very fine powders meant for dusting entryways and such. These types of insecticides will also contain anti-caking agents so that they are free flowing as well as many containing diatomaceous earth (DE) to act as an abrasive which removes the waxy coating from the insect's exoskeleton. Without the waxy coating, the insect dessicates from water loss.<ref>https://www.troublefreepool.com/threads/boric-acid-the-easy-way.37456/post-832022</ref>
 +
 +
DE (uncalcined) and some anti-caking agents are not considered hazardous (in fact, uncalcined DE is a food additive), and therefore are not reportable in the MSDS. That is why they can say it's 100% boric acid powder even though it might be 60% boric acid and 40% other inert ingredients.
 +
 +
Also the insecticide can have a blue dye added to it so you can see where you’ve sprayed it as a bug killer.<ref>https://www.troublefreepool.com/threads/boric-acid-no-no.196020/post-1728248</ref>
  
 
===How to Add Borates Using Borax and Muriatic Acid===
 
===How to Add Borates Using Borax and Muriatic Acid===
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==How to Test for Borates in Pool Water==
 
==How to Test for Borates in Pool Water==
  
−
The exact level of borates is not critical and just needs to be in the 30 to 50 ppm range. We recommend using LaMotte Insta-Test Borate Test Strips. They aren't great, and not very precise, but they seem to be the best available choice that isn't expensive.
+
The exact level of borates is not critical and just needs to be in the 30 to 50 ppm range. We recommend using [https://tftestkits.net/Borates-Test-Strips-p29.html Taylor Borates Test Strips]. The test strips are the best inexpensive choice for testing borates.
  
 
A mannitol test for borates has been developed by some creative members. It is a bit complex and you can read about it [https://www.troublefreepool.com/threads/new-borate-drop-test-at-piscines-apollo-vs-test-strip.33440/page-7#post-1270754 here].
 
A mannitol test for borates has been developed by some creative members. It is a bit complex and you can read about it [https://www.troublefreepool.com/threads/new-borate-drop-test-at-piscines-apollo-vs-test-strip.33440/page-7#post-1270754 here].
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Boron is an essential nutrient so the body takes in what it needs and excretes the rest, though this process has its limits which is why almost anything is toxic if given in high enough doses. This excretion process is fairly efficient for mammals that use urine primarily to excrete excess nitrogen as urea, but for insects they excrete solid uric acid so do not excrete boron efficiently which is why boron is far more toxic to them.<ref>https://www.troublefreepool.com/threads/are-borates-safe-to-use.14157/post-464493</ref>
 
Boron is an essential nutrient so the body takes in what it needs and excretes the rest, though this process has its limits which is why almost anything is toxic if given in high enough doses. This excretion process is fairly efficient for mammals that use urine primarily to excrete excess nitrogen as urea, but for insects they excrete solid uric acid so do not excrete boron efficiently which is why boron is far more toxic to them.<ref>https://www.troublefreepool.com/threads/are-borates-safe-to-use.14157/post-464493</ref>
 +
 +
Some threads on Borate safety:
 +
*[https://www.troublefreepool.com/threads/are-borates-safe-to-use.14157/ Are Borates Safe to Use?]
 +
*[https://www.troublefreepool.com/threads/borates-and-dogs.88532/post-759932 Borates and Dogs]
 +
*[https://www.troublefreepool.com/attachments/boric_acid-pdf.558452/ Birch RG (2013a) Boric acid as a swimming pool buffer]
  
 
==Are Borates an Algaecide?==
 
==Are Borates an Algaecide?==
 
While Borates tend to have a minimal effect as an algaecide one shouldn’t utilize them to prevent algae. The boron concentration that that is required to noticeably reduce the risk of algae<ref>https://www.troublefreepool.com/threads/other-things-that-claim-to-reduce-chlorine-usage.65703/#post-557324</ref> is far higher than what is generally considered safe so we generally don’t utilize them to prevent algae, we only focus on the benefits for buffering pH changes.
 
While Borates tend to have a minimal effect as an algaecide one shouldn’t utilize them to prevent algae. The boron concentration that that is required to noticeably reduce the risk of algae<ref>https://www.troublefreepool.com/threads/other-things-that-claim-to-reduce-chlorine-usage.65703/#post-557324</ref> is far higher than what is generally considered safe so we generally don’t utilize them to prevent algae, we only focus on the benefits for buffering pH changes.
 +
 +
==What are the algaestatic properties of borates==
 +
 +
The algaestatic properties of borates is over-stated at 50ppm. Borates act more as an "inhibitor" than biocidal agent. In other words, the presence of boron in the water at 50ppm interferes with certain cellular processes going on inside the algae (likely inhibiting key enzymes that contain diol organic structures). By causing this interference, the algae is either slowed in it's replication or it's reproduction is stopped.<ref> https://www.troublefreepool.com/threads/borax-as-algestat.128544/post-1136923</ref>
 +
 +
Borates only become truly algaestatic at concentrations above 100ppm (and really closer to 200ppm) which would make the water unhealthy to swim in for large mammals and humans. Above 100ppm, there could be chronic toxic effects on very small children (babies) and pets (dogs or cats) that might accidentally (or intentionally) ingest pool water.
  
 
==Is Borax and Baking Soda the same thing==
 
==Is Borax and Baking Soda the same thing==
 
Borax and Baking Soda are two different chemicals.  Borax will increase the pH of the water without increasing the total alkalinty.  Baking soda on the other hand will help increase your total alkalinty.
 
Borax and Baking Soda are two different chemicals.  Borax will increase the pH of the water without increasing the total alkalinty.  Baking soda on the other hand will help increase your total alkalinty.
 +
 +
===Borates and Adjusted Alkalinity===
 +
 +
Adjusted TA = TA – (CYA X CYA C.F) – (Borate x Borate CF)
 +
 +
Borate C.F (correction factor) based on pH.
 +
 +
pH.......CF
 +
 +
7.2.....0.051
 +
 +
7.4.......0.0786
 +
 +
7.6......0.1248
 +
 +
7.8......0.1989
 +
 +
Cyanuric Acid correction factor based on pH.
 +
 +
pH........CF
 +
 +
7.0.......0.22
 +
 +
7.1.......0.24
 +
 +
7.2.......0.26
 +
 +
7.3.......0.28
 +
 +
7.4.......0.30
 +
 +
7.5.......0.32
 +
 +
7.6.......0.33
 +
 +
7.7.......0.34
 +
 +
7.8.......0.35
 +
 +
7.9.......0.36
 +
 +
For example, if the pH = 7.6, TA = 90, Borate = 50 and CYA = 70, the adjusted alkalinity is 90 - (70 x 0.33) – (50 x 0.1248) = 60.66.
 +
 +
=A Pool Care Experts View of Borates in Pools=
 +
 +
The following was written by Kim Skinner, aka OnBalance, and published with his permission.
 +
 +
==A Bit of History About Borate Use in Pools==
 +
There are a lot of bold claims about the benefits of adding borate (boron) to swimming pools. Are they true? Well, some are true, and some are not.
 +
 +
The following information about borate in pools comes from Kim Skinner and John Cardall, who added borax (borate) to pools as early as 1966 as teenagers while working for Pool Chlor Inc., a pool service company in southern California. At that time, Pool Chlor was maintaining more than 1000 residential pools and using chlorine gas as their primary sanitizer. As many know, chlorine gas is very acidic and lowers the pH when added. In 1960, two chemists who owned Pool Chlor realized that (carbonate) alkalinity and CYA were good buffers at pH levels below 7.2, but not highly effective at pH 8.0. They searched for a chemical that would increase buffering at a higher pH (8.0-8.2) and learned that adding borax would help. The graphs below illustrate the buffering differences.
 +
 +
[[File:PH Buffer Capacity1.png|thumb]]
 +
 +
[[File:PH Buffer Capacity2.png|thumb]]
 +
 +
It was soon determined that about 50 ppm of boron was helpful along with an adequate amount of total alkalinity to properly buffer the generated acid. With a starting pH of about 8.0 to 8.2, the presence of borate improved buffering (neutralizing) the acid being produced by the chlorine gas.
 +
 +
Thus, Pool Chlor began adding borax systematically to their pools in about 1962. (That is more than 20 years before a patent was applied for by a chemical company in Florida).
 +
 +
==Additional Benefits of Borate==
 +
It is also known that borate helps buffer against a rising pH when alkaline products are added, such as soda ash, bleach, or cal hypo. One benefit is that, under certain conditions such as hard water, the water is not as likely to turn cloudy when those products are added to water.
 +
 +
It is interesting to note that some eye soothing solution products contain boric acid and sodium borate and have a pH of about 8.0. Customers reported that the pool water containing borate results in less eye irritation.
 +
Some pool owners claimed that the water was so clear that it “sparkled.” Truthfully, we think pool water can sparkle without borate, but it may play a role in that, too! (A possible reduction in surface tension may be why).
 +
There are also reports (and some supporting science) that having borate in water helps to minimize calcium build-up in SWCG units.
 +
 +
==What Claims are Not True?==
 +
Borate will NOT reduce chlorine costs by 30% to 50% as is being claimed. It is generally known that residential pools lose, on average, about 1 to 2 ppm of chlorine per day. According to several service companies, residential pools generally lose the same amount of chlorine daily whether they contain borate or not. And the suggestion to maintain lower chlorine levels when using borate is risky and problematic.
 +
 +
It is incorrect to suggest that Borate “prevents” or “stops” the pH from rising. While borate can slow down or reduce the pH rise somewhat when alkaline chemicals are added, it is only temporary. Generally, the pH will eventually rise above 7.6 (and up to 8.3) if the (carbonate) alkalinity is 80 to 120 ppm and if no acidic chemicals are being added. That is the general reality of water chemistry.
 +
 +
It is misleading to suggest that borates (50 ppm boron) will eliminate or prevent algae. Pool water requires an adequate amount of a sanitizer to kill and prevent algae. Borate will not do that. When a sanitizer is no longer present, the water will soon grow algae and bacteria. However, borate is an algaestat (not an algaecide) and can inhibit and slow down algae growth, which in turn, can reduce chlorine costs in that situation.
 +
 +
Borate does not eliminate or prevent calcium nodules. Calcium nodules are caused by excessive shrinkage cracks and/or delamination (bonding failure), not by out-of-balance pool water. And borate does nothing to change that.
 +
Yes, there are some good benefits to using borate (by adding borax or boric acid). But we should not tarnish its’ appeal and benefits by making false claims, exaggerations, or misleading disinformation.
 +
 +
We thank Richard Falk for his input and for the two graphs.

Latest revision as of 00:49, 17 May 2024

Why should one use Borates

Adding borates to your pool can improve your experience with your pool, but is completely optional.

The key benefit of adding borates to your pool is to help slow pH increase. If you do plan to use borates, wait until everything else is settled down before adding borates, especially TA and PH, and you have a good understanding of how your pool chemistry works.

The only situations where we specifically recommend using borates are for pools with a negative edge or other very large water feature creating huge amounts of aeration and for spas using the dichlor and then bleach method.

All that said, borates have proven popular with many pool owners.

Benefits of using Borates

  • More stable pH due to slowing pH increase
  • Helps prevent scaling in a SWG cell
  • Silky water feel
  • More water sparkle

The Borate Pool Opening in Aqua Magazine discusses how borates can limit pH rise while a pool is closed for the winter. High pH while a pool is closed can cause scaling. For those that find their pools with very high pH at Spring opening borates may benefit with the pool open or closed.

Borates buffering pH rise

1÷(1+10^(pKa – pH)) = borate percentage.

1÷(1+10^(9.15 – pH)) X 100 = borate percentage.

pH.....Borate.....Boric Acid.

7.2.....1.1%..........98.9%

7.4.....1.7%..........98.3%

7.6.....2.7%..........97.3%

7.8.....4.3...........95.7%

8.0.....6.6...........93.4%.

As you can see from this chart, most of the borate is in the form of boric acid, which contributes to the total acidity.

Total acidity is the same concept as total alkalinity but total acidity buffers pH rise whereas total alkalinity buffers pH drop.

Borates at 50 ppm provide as much protection from pH rise as 221 ppm of TA provides against pH drop.

Downfalls of Borates

  • Additional expense
  • Concerns about risks to pets
  • Not a magical potion to solve all pool woes

How do Borates Affect a SWG?

Borates can act as a mild algaecide and so people usually see that “boost” in efficiency because borates can make it harder for algae to replicate. Borates is also a strong buffer against high pH changes inside the cell as the pKa is around 9.0 for the boric acid/borate ion buffer system. Keeping the pH in check means that calcium scaling is less likely and thus the cell can run without getting coated with scale. Scale reduces the efficiency of the cell.[1]

Hydroxide is produced in the cell.

2H2O --> H2 + 2OH-

2 water –> Hydrogen gas + 2 hydroxide.

The hydroxide converts bicarbonate to carbonate.

HCO3- + OH- --> H2O + CO3^2-

Bicarbonate + hydroxide --> water + carbonate.

Then, the carbonate connects to calcium and you get calcium carbonate.

Ca^2+ + CO3^2- --> CaCO3

Calcium + carbonate --> calcium carbonate.

Boric acid protects from pH rise by accepting and binding to the hydroxides produced in the cell due to the production of hydrogen.

B(OH)3 + OH- --> B(OH)4-

Boric acid + hydroxide --> Borate.

So, it's really boric acid and total acidity that provides the protection from pH rise and cell scaling.

How to add Borates to your Pool

We recommend maintaining borates between 30 and 50 ppm.

Borates leave the water primarily through splash out and backwashing. [2] Borates are also lost when draining the pool during winter closings. Borates do not degrade.

That normally means checking and raising the borate level to around 50 each spring at the start of swimming season, so that it will still be above 30 come fall.

Before you start on borates, adjust your TA level toward the low end of the appropriate range for your pool type. See the Recommended Levels chart for appropriate levels.

There are two approaches to adding borates to the pool: boric acid, or a combination of Borax and muriatic acid. Using boric acid is just slightly more expensive, in most cases, and much easier. Borax and muriatic acid takes more effort and handling that much acid is just slightly risky, but saves just a little money if you shop carefully.

How to Add Borates Using Boric Acid

Calculate, using PoolMath, how much Boric acid you will need for 50 ppm.

Boric acid can be purchased from DudaDiesel and The Chemistry Store. Granular is much easier to work with than powdered. Technical grade is fine.

Distribute the boric acid across the surface of the pool. Keep the pump running for at least one hour after adding boric acid, and then test the pH and adjust if needed.

Boric acid will lower the pH slightly. Usually the pH change is small enough that no further adjustment is required.

Proteam Supreme Plus is Sodium Tetraborate Pentahydrate and will significantly raise your TA while adding borates to the water. We recommend you use Boric Acid, which adds a minimal amount to your total alkalinity.[3]

Do Not Use Roach and Ant Killer for Boric Acid

Roach and Ant killer can contain boric acid and labels may say it is 99% boric acid and 1% inert. However, they will be very fine powders meant for dusting entryways and such. These types of insecticides will also contain anti-caking agents so that they are free flowing as well as many containing diatomaceous earth (DE) to act as an abrasive which removes the waxy coating from the insect's exoskeleton. Without the waxy coating, the insect dessicates from water loss.[4]

DE (uncalcined) and some anti-caking agents are not considered hazardous (in fact, uncalcined DE is a food additive), and therefore are not reportable in the MSDS. That is why they can say it's 100% boric acid powder even though it might be 60% boric acid and 40% other inert ingredients.

Also the insecticide can have a blue dye added to it so you can see where you’ve sprayed it as a bug killer.[5]

How to Add Borates Using Borax and Muriatic Acid

Borax can be found at grocery stores and muriatic acid at hardware stores. Make sure you check the strength of the muriatic acid, using half strength acid when you thought it was full strength 31.45% can lead to problems with pH.

Calculate, using PoolMath, how much Borax and Muriatic Acid you will need for 50 ppm. Verify the amounts using PoolMath after purchase and double check the weights on the Borax boxes and strength of the Muriatic acid. (Is there only one size Borax box?)

The process for adding the Borax and Muriatic Acid is:

  • pre-dissolve 3 1/2 boxes (Do we want to specify box or weight?) of Borax in a bucket
  • pour one gallon of 31.45% muriatic acid slowly in front of a return jet with the pump running
  • pour the dissolved Borax in the bucket slowly into the pool
  • brush the entire pool if you see any undissolved Borax to mix it in and get it dissolved.
  • For pools smaller than 10,000 gallons it is better to add a half gallon of 31.45% muriatic acid followed by about 1 3/4 boxes of Borax each time.

Repeat the process (at what interval?) until you have added the correct total amounts to the pool. The final dose will, of course, be smaller.

24 hours later, test the pH and adjust as needed.

How to Test for Borates in Pool Water

The exact level of borates is not critical and just needs to be in the 30 to 50 ppm range. We recommend using Taylor Borates Test Strips. The test strips are the best inexpensive choice for testing borates.

A mannitol test for borates has been developed by some creative members. It is a bit complex and you can read about it here.

Borates and Health Concerns

Borates have in the past had a reputation for being unsafe for both humans and pets, mostly dogs. While very high levels can pose some risks TFP Suggested Levels are safe for both. A 100 pound dog would need to drink 8 liters (over 8 quarts) of 50 ppm borate pool water every day just to be at the No Observed Adverse Effect Limit (NOAEL). The level seen for first symptoms is 3 times higher than this amount. And this is literally drinking every day since borates are excreted from the body and do not accumulate so the daily intake level where problems would occur is that which is higher than the rate at which the body flushes out borates.

Boron is an essential nutrient so the body takes in what it needs and excretes the rest, though this process has its limits which is why almost anything is toxic if given in high enough doses. This excretion process is fairly efficient for mammals that use urine primarily to excrete excess nitrogen as urea, but for insects they excrete solid uric acid so do not excrete boron efficiently which is why boron is far more toxic to them.[6]

Some threads on Borate safety:

Are Borates an Algaecide?

While Borates tend to have a minimal effect as an algaecide one shouldn’t utilize them to prevent algae. The boron concentration that that is required to noticeably reduce the risk of algae[7] is far higher than what is generally considered safe so we generally don’t utilize them to prevent algae, we only focus on the benefits for buffering pH changes.

What are the algaestatic properties of borates

The algaestatic properties of borates is over-stated at 50ppm. Borates act more as an "inhibitor" than biocidal agent. In other words, the presence of boron in the water at 50ppm interferes with certain cellular processes going on inside the algae (likely inhibiting key enzymes that contain diol organic structures). By causing this interference, the algae is either slowed in it's replication or it's reproduction is stopped.[8]

Borates only become truly algaestatic at concentrations above 100ppm (and really closer to 200ppm) which would make the water unhealthy to swim in for large mammals and humans. Above 100ppm, there could be chronic toxic effects on very small children (babies) and pets (dogs or cats) that might accidentally (or intentionally) ingest pool water.

Is Borax and Baking Soda the same thing

Borax and Baking Soda are two different chemicals. Borax will increase the pH of the water without increasing the total alkalinty. Baking soda on the other hand will help increase your total alkalinty.

Borates and Adjusted Alkalinity

Adjusted TA = TA – (CYA X CYA C.F) – (Borate x Borate CF)

Borate C.F (correction factor) based on pH.

pH.......CF

7.2.....0.051

7.4.......0.0786

7.6......0.1248

7.8......0.1989

Cyanuric Acid correction factor based on pH.

pH........CF

7.0.......0.22

7.1.......0.24

7.2.......0.26

7.3.......0.28

7.4.......0.30

7.5.......0.32

7.6.......0.33

7.7.......0.34

7.8.......0.35

7.9.......0.36

For example, if the pH = 7.6, TA = 90, Borate = 50 and CYA = 70, the adjusted alkalinity is 90 - (70 x 0.33) – (50 x 0.1248) = 60.66.

A Pool Care Experts View of Borates in Pools

The following was written by Kim Skinner, aka OnBalance, and published with his permission.

A Bit of History About Borate Use in Pools

There are a lot of bold claims about the benefits of adding borate (boron) to swimming pools. Are they true? Well, some are true, and some are not.

The following information about borate in pools comes from Kim Skinner and John Cardall, who added borax (borate) to pools as early as 1966 as teenagers while working for Pool Chlor Inc., a pool service company in southern California. At that time, Pool Chlor was maintaining more than 1000 residential pools and using chlorine gas as their primary sanitizer. As many know, chlorine gas is very acidic and lowers the pH when added. In 1960, two chemists who owned Pool Chlor realized that (carbonate) alkalinity and CYA were good buffers at pH levels below 7.2, but not highly effective at pH 8.0. They searched for a chemical that would increase buffering at a higher pH (8.0-8.2) and learned that adding borax would help. The graphs below illustrate the buffering differences.

PH Buffer Capacity1.png
PH Buffer Capacity2.png

It was soon determined that about 50 ppm of boron was helpful along with an adequate amount of total alkalinity to properly buffer the generated acid. With a starting pH of about 8.0 to 8.2, the presence of borate improved buffering (neutralizing) the acid being produced by the chlorine gas.

Thus, Pool Chlor began adding borax systematically to their pools in about 1962. (That is more than 20 years before a patent was applied for by a chemical company in Florida).

Additional Benefits of Borate

It is also known that borate helps buffer against a rising pH when alkaline products are added, such as soda ash, bleach, or cal hypo. One benefit is that, under certain conditions such as hard water, the water is not as likely to turn cloudy when those products are added to water.

It is interesting to note that some eye soothing solution products contain boric acid and sodium borate and have a pH of about 8.0. Customers reported that the pool water containing borate results in less eye irritation. Some pool owners claimed that the water was so clear that it “sparkled.” Truthfully, we think pool water can sparkle without borate, but it may play a role in that, too! (A possible reduction in surface tension may be why). There are also reports (and some supporting science) that having borate in water helps to minimize calcium build-up in SWCG units.

What Claims are Not True?

Borate will NOT reduce chlorine costs by 30% to 50% as is being claimed. It is generally known that residential pools lose, on average, about 1 to 2 ppm of chlorine per day. According to several service companies, residential pools generally lose the same amount of chlorine daily whether they contain borate or not. And the suggestion to maintain lower chlorine levels when using borate is risky and problematic.

It is incorrect to suggest that Borate “prevents” or “stops” the pH from rising. While borate can slow down or reduce the pH rise somewhat when alkaline chemicals are added, it is only temporary. Generally, the pH will eventually rise above 7.6 (and up to 8.3) if the (carbonate) alkalinity is 80 to 120 ppm and if no acidic chemicals are being added. That is the general reality of water chemistry.

It is misleading to suggest that borates (50 ppm boron) will eliminate or prevent algae. Pool water requires an adequate amount of a sanitizer to kill and prevent algae. Borate will not do that. When a sanitizer is no longer present, the water will soon grow algae and bacteria. However, borate is an algaestat (not an algaecide) and can inhibit and slow down algae growth, which in turn, can reduce chlorine costs in that situation.

Borate does not eliminate or prevent calcium nodules. Calcium nodules are caused by excessive shrinkage cracks and/or delamination (bonding failure), not by out-of-balance pool water. And borate does nothing to change that. Yes, there are some good benefits to using borate (by adding borax or boric acid). But we should not tarnish its’ appeal and benefits by making false claims, exaggerations, or misleading disinformation.

We thank Richard Falk for his input and for the two graphs.

  1. ↑ https://www.troublefreepool.com/threads/borates-and-swg.194373/post-1713562
  2. ↑ https://www.troublefreepool.com/threads/do-borates-degrade.261349/post-2285195
  3. ↑ https://www.troublefreepool.com/threads/proteam-supreme-plus-raised-ta.214268/post-1875423
  4. ↑ https://www.troublefreepool.com/threads/boric-acid-the-easy-way.37456/post-832022
  5. ↑ https://www.troublefreepool.com/threads/boric-acid-no-no.196020/post-1728248
  6. ↑ https://www.troublefreepool.com/threads/are-borates-safe-to-use.14157/post-464493
  7. ↑ https://www.troublefreepool.com/threads/other-things-that-claim-to-reduce-chlorine-usage.65703/#post-557324
  8. ↑ https://www.troublefreepool.com/threads/borax-as-algestat.128544/post-1136923
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