So you want to add borates to your pool--Why and How

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Conan12 said:
Hoosierrun - any update on the discoloration? We are in the process of building our first pool and also are going with the blue granite pebble sheen. Has anyone else with a pebble sheen finish had a similar experience as hoosierrun? Thanks in large part to the wealth of information provided on this site, I had planned to use boric acid to add borates to our pool and want to be sure to apply properly to avoid discoloration or other unwanted side effects.
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Sorry, I missed this question from October. The discoloration has almost disappeared, although I my coating is still not a uniform blue across the entire pool from bottom up and from end to end. However, you reallly have to look close on a calm day to notice that (easier with pumps off).

My suggestion: If you are using crystal boric acid to add borates to a colored pool surface, mix up batches in a bucket of water and slowly add it into the skimmer with the pump running. It is fairly PH neutral and that shouldn't cause a problem with anything. I could never get the crystals to completely disolve in the bucket of water (over saturated), plus I was trying to get the job done quickly.

It seems to me that with colored pool surfaces, you have to be more careful not to allow chemical solids to touch the surface. I've become fairly disciplined in disolving everything in a bucket of water and pouring slowly a couple of feet from where the jets discharge.

BTW, the borates are working out well and I think it was money well spent.
 
I don't think the borates will reduce maintenance over the winter -- why do you think it would reduce the need for maintenance? Also, if you have winter rain overflow, you'll just end up diluting some of the borates and have to add more later. It probably makes more sense to add it in the spring.

If your water temperature drops over the winter, you may not need to brush very often and the chlorine should last a lot longer as well. Maintenance over the winter should be much easier than during the summer.
 
borax.jpg

Guess What I did yesterday?

18 Boxes Borax & about 5 1/3 gallons acid

PH dead on 7.5

Water looks amazing! I will have to wait and see if all the other benefits work out! Hardest part of project was finding 18 boxes of Borax.

Thank You very much for the Guide it was great!
 
1) more stable pH
2) Algaestatic properties
3) reduced chlorine usage
4) silkier feeling water--less skin and eye irritation
5) clearer, 'sparkling' water
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Please explain how it does all these things. I'm not saying I doubt these claims, I'm just curious to know how it fulfills these claims.

Thanks
 
1) more stable pH
Boric acid is a weak acid and any weak acid that is partially dissociated will be a pH buffer. The carbonate buffer system in pools has two pKa at roughly 6.3 and 10.2 which means the pH buffering is strongest near these values. The pKa for boric acid is roughly 9.1. You can see the relative buffer strength for these buffers as well as for Cyanuric Acid (CYA) which is also a pH buffer in the thread pH Buffer Capacity. Boric acid is most useful as a pH buffer against a rise in pH since the buffering gets stronger as the pH rises. The carbonates and CYA are more useful as buffers against a drop in pH.

2) Algaestatic properties
See Table 18 in this link that shows how boric acid inhibits algae growth. At 50 ppm (Boron), it is not nearly as strong an algaecide as traditional algaecides, but it does take some of the edge off of algae growth, primarily for green algae (not so much for black or yellow/mustard algae).

3) reduced chlorine usage
This only occurs if one has low level algae growth that would otherwise consume chlorine. If one maintains the appropriate minimum Free Chlorine (FC) level that is at least 7.5% of the Cyanuric Acid (CYA) level in non-SWG pools, then algae should be killed faster than it an reproduce so the borates shouldn't have any noticeable effect on chlorine usage.

4) silkier feeling water--less skin and eye irritation
This is debatable. There can be less eye irritation from having the pH be more stable, but a silkier water feel is subjective. It is possible for the borates to change the surface tension of the water (though that is an open question -- I've seen a flattened meniscus when using it, but some others have reported sources that claim there is no change in surface tension).

5) clearer, 'sparkling' water
There does seem to be more sparkle to the water after adding it, but we're not sure why. It might be reduced surface tension which changes the wave angles for a surface that might reflect more, but that's just speculation.
 
09659 said:
Seems nice, but not particularly necessary.
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Just so.

The main time it wanders close to "necessary" territory is when you have a negative edge pool, or other water feature with major amounts of aeration. Using borates allows you to lower TA further than you can lower TA without borates (because of the additional buffering) and lower TA reduces the rate of PH increase.
 

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The pH buffering against a rise in pH is particularly useful in saltwater chlorine generator pools not only because their pH tends to rise so this extra buffering lets one add acid less frequently (it doesn't change the total amount of acid needed over time, however), but it also significantly reduces the amount of calcium carbonate scaling at the hydrogen gas generation plate in the SWG cell because it roughly cuts down the amount of pH rise in half. The other way to reduce scaling in the SWG cell is to operate with a lower Calcite Saturation Index (CSI), but going too low with that approach risks dissolving of plaster surfaces.
 
I have had a interesting day yesterday. I read all 25 pages with interest and maybe even suspicion.
Boric acid sounded dangerous at first until I realized. where did I hear of it before?
oh ya I believe everybody on this forum has had it put into their eyes when they were born. yes it is given
to all infants in their eyes at a dilution of 1 boric acid part to 10 parts distilled water solution, or something less like 3%.
anybody know for sure? it is the only approved acid for eyes from what I remember.

however as I read every bodies becoming chemist creating the boric acid in their pool by
mixing the borax with the MA muratic acid. by product being salt...reason some have described
their water feeling softer. dog onit just add a bag of salt if you want it soft.

I know I use the borax with honey as a ant killer and it is sold that way at your local hardware store.
acidity level is 9.4 but pure borax can equalize it in your pool.

I did like that someone found the 50 pound bag of boric acid at their local AG agriculture supply
house for $47 and it is used for keeping insects under control in chicken houses. you might check your
local AG supplier too.

I was just happy when I used some borax correct my PH last year. 6 lbs of it was all that I needed.
my pool has been quite stable since last year. and it was fine opening this last week. I can not imagine what
50 ppm would do but I am aiming that way. just not sure if I can find a local AG supply bag yet.
but the duda diesel is not far away from my location I may drive there and save shipping......

just a note, where some people are constantly adding acid to neutralize their water boric acid may be
the way to do it slowly......
 
Yes, boric acid is used in eye washes. And in concentrated powdered form it is used as an insect killer. You can read more about boron/borate/boric acid safety in the thread Are Borates Safe to Use?

Note that adding borax and acid doesn't actually produce that much of a borate salt. At pool pH, it's mostly boric acid and some borate ion (and sodium ion). So it isn't the same as sodium chloride salt. You can instead buy and add boric acid directly and need little pH adjustment since boric acid is a weak acid where 50 ppm Borates added from boric acid only drops the pH from 7.5 to 7.2 at usual TA levels.

Note that having 50 ppm Borates in the pool can slow down the rate of pH rise, but it should not reduce the amount of acid you need to add. To reduce the amount of acid needed (per unit time), you need to lower the TA level since that is a measure of the over-carbonation of the pool that is causing carbon dioxide to outgas and that causes the pH to rise.
 
I guess I consider my self lucky. last year I never had to add acid between rains and tap water added.
my pool this year is already sparkling like a rainbow in this mornings sun. I will over time add to the
mix somehow. just the thought of less chlorine generated...SWG would mean less power used and a
even longer life on my 20 year old unit. the 50ppm borates is the way to go.
thanks to you and others here I have learned a enough about pool maintenance I feel dangerous...hahaha

also at the 8' deep end, the water is so clear I could easily see a nickel, dime or quarter on the bottom and
tell if it is heads or tails. I am wondering how I can improve on that.
Ed
 
In reading the first page with the instructions to add borates, why is it necessary to wait 48 hours to test for the borates level? Filter has ran 24 hours straight, will that not have the water sufficiently turned?
 
I agree with you since the chemicals do dissolve quickly (they aren't like cyanuric acid that dissolves slowly) and a pool with decent circulation will mix chemicals fairly quickly. In fact, I would be surprised if you wouldn't get a correct reading after an hour if you have good circulation in your pool. I've added boric acid to my pool and taken readings within an hour at high pump speed and measured what I expected. So I'm not sure why the original instructions in the first post say to wait so long.
 

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