Received Granular boric acid anhydrous from duda diesel

[Ab6349]

Hello, I have been learning lots of good info from this website. We haven't had the pool very long, in fact its only been a few months. I am looking to add borates to the pool to help with the ph fluctuations. I ordered granular Boric acid from duda diesel and received Granular boric acid anhydrous. I researched it a little and it looks like it is boric oxide. Anybody know more about this stuff?

 

[Patrick_B]

Welcome to TFP!

What else do you want to know? It's mildy Algae preventative, it's a pH stabilizer, and a lot of people think it makes the water feel better, and look better. I think the latter qualities are subjective to individual people, but thats a start. It's also completely optional, but very helpful with some Salt Chlorine Generator pools. My advice to people is always that it is optional, and don't add it to your pool until you have a good feel and grasp of all the chemistry/balance issues. Many new members presume you need it, or it's essential because of "BBB Pool Care". It's actually why we don't use the term anymore, but refer to what we teach as TFPC.

What kind of pH fluctuations are you having?

 

[Ab6349]

Thanks for the quick reply. My question is that its labeled Granular Boric Acid ANHYDROUS. This is not the same as Boric acid. Is this the same stuff that everyone has been using from dudadiesel or has dudadiesel changed?

 

[JoyfulNoise]

Thanks for the quick reply. My question is that its labeled Granular Boric Acid ANHYDROUS. This is not the same as Boric acid. Is this the same stuff that everyone has been using from dudadiesel or has dudadiesel changed?

Boric acid is always anhydrous, there is no water of crystallization in it. Sodium tetraborate (borax) comes in various hydrated forms with decahydrate being the most common form of the salt.

Duda only sells anhydrous boric acid. That is exactly what my 50lb bucket says. PoolMath also only assumes anhydrous boric acid for calculations.

 

[Ab6349]

Thanks.m for the input. I still am concerned. I have since searched the forum and found a few of chem geeks' posts and he said not to use the boric oxide(boric acid anhydrous). Not sure if Duda just recently changed what they are selling.

 

[duraleigh]

I know this is off the subject but I am curious just how much your pH fluctuates? Can you post some test numbers?

 

[JoyfulNoise]

Thanks.m for the input. I still am concerned. I have since searched the forum and found a few of chem geeks' posts and he said not to use the boric oxide(boric acid anhydrous). Not sure if Duda just recently changed what they are selling.

No. You are confusing terms.

Boric oxide (B2O3) is not the same as boric acid (H3BO3). Boric oxide is boric acid anhydride - boric acid is thermally decomposed in a stepwise reaction that releases water molecules with metaboric acid as an intermediate-

H3BO3 → HBO2 + H2O
2 HBO2 → B2O3 + H2O

This is not the same as boric acid, anhydrous (note the comma) which, in chemistry terms, refers to a compound that has no water of crystallization in it. In other words, anhydride is not the same thing as anhydrous.

As for Duda Diesel's product, my 50lbs pail is 2 years old and says "boric acid, anhydrous" on it. It is what they sell and I have been using it for years now. It is perfectly safe to use in a pool as describe in the sticky thread on how to add borates.

 

[Ab6349]

Thanks again. I understand what you are saying and it makes sense. I guess I got confused. I googled "Anhydrous Boric Acid" and it says its Boric Oxide. I requested a COA from duda diesel and the top says its boric acid but the test says its boric oxide.
View attachment boric acid coa.pdf

 

[JoyfulNoise]

Thanks again. I understand what you are saying and it makes sense. I guess I got confused. I googled "Anhydrous Boric Acid" and it says its Boric Oxide. I requested a COA from duda diesel and the top says its boric acid but the test says its boric oxide.
View attachment 64229

Again, the terminology can be confusing because of the history of the chemistry of borates. They form very complex compounds and, unfortunately, early chemists used many of the same terms for different substances interchangeably.

That assay you received says boric oxide because that is the assay method used to determine purity. A boric acid sample is measured by thermally decomposing it into boric oxide and then the boric oxide is weighed and impurities are determined. If you use the chemical equations in my previous post you'll find that it takes two moles of boric acid (H3BO4) to be converted into one mole of boric oxide (B2O3). Using their respective molecular weights -

(69.62/61.83) * 0.5 = 0.563

So, 100gm of boric acid will be thermally decomposed into 56.3gm of boric oxide if the sample is 100% pure. As you can see from their assay analysis, the percentage boric oxide they achieve is 56.6% which is well within their specs and very close to theoretical purity. Based on that assay, the boric acid is 99.995% pure. So, all that assay is telling you is that the boric acid has the purity they claim it to be.

 

[DudaDiesel]

Thanks.m for the input. I still am concerned. I have since searched the forum and found a few of chem geeks' posts and he said not to use the boric oxide(boric acid anhydrous). Not sure if Duda just recently changed what they are selling.

Duda here.

So several things going on:

1) JoyfulNoise is correct about the difference between anhydrous and anhydride.
2) We have since removed the word anhydrous from our newer labels, to avoid confusion. Product is unchanged.

3) The most confusing part - the Certificate of Analysis we provide shows boric oxide, not boric acid (and it shows it at ~56%, varies per batch)

The reason for this is there is not an easy test to calculate the concentration of boric acid. Not cost effectively, at least.
So instead, the boric oxide form is taken, it is tested, and then the results of this test allow them to mathematically determine what the concentration of the boric acid product will be. Boric oxide at 56.25% means that the boric acid will be 99.9%.


TL;DR - the product we carry is Boric acid, not boron oxide; it has been the same product since 2010 and made from the same manufacturer since 2013. We've just never been the best at making labels.

 

[November Cadet]

Duda here.

So several things going on:

1) JoyfulNoise is correct about the difference between anhydrous and anhydride.
2) We have since removed the word anhydrous from our newer labels, to avoid confusion. Product is unchanged.

3) The most confusing part - the Certificate of Analysis we provide shows boric oxide, not boric acid (and it shows it at ~56%, varies per batch)

The reason for this is there is not an easy test to calculate the concentration of boric acid. Not cost effectively, at least.
So instead, the boric oxide form is taken, it is tested, and then the results of this test allow them to mathematically determine what the concentration of the boric acid product will be. Boric oxide at 56.25% means that the boric acid will be 99.9%.


TL;DR - the product we carry is Boric acid, not boron oxide; it has been the same product since 2010 and made from the same manufacturer since 2013. We've just never been the best at making labels.

I just bought 75 lbs of the stuff from you guys! Great price and quick shipping.