Excellent Article On The Benefits And Chemistry Of Borates In Swimming Pools

[Chuck_Davis]

I highly recommend borates in pools (and hot tubs). This is an excellent article describing the chemistry and benefits. Don't use the 20 Mule Team method (been there, done that) and don't pay pool store prices. Order in bulk from Duda Diesel (link in the article). Get the Taylor test strips (they use a new methodology).

Benefits of Using Borates

• Keeps the pH of the water from going up (pH buffer against rises in pH)
• Helps prevent algae (it is an algaestat, not an algaecide)
• Lowers chlorine demand (preventing algae lowers the need for chlorine)
• Helps protect HOCl (hypochlorous acid – the killing form of free chlorine) from UV destruction
• Water feels softer and silkier [Opinion]
• Water looks clearer and sparkles [Opinion]

Using borates with an SWG or ECG

Borate is a buffer against pH increase so this means less calcium carbonate scaling on the hydrogen gas (H2) generation plate (negative electrode) of the SWG. That should be it’s only side effect and it is a benefit. Also, keeping 50 ppm of borate lowers the recommendation that free chlorine should be 7.5% of CYA to 5% of CYA. This is a minimum of 33% less chlorine. [Opinion]

Guide to Borate for Pools • Pool Chemistry Training Institute

Borates are highly recommended for pools. Adding borate is a one-time thing. Borate does not decompose, get used up or expire. Borate is only lowered by water

poolchemistrytraininginstitute.com

 

[Mdragger88]

This article must be quite old- the price of boric acid from duda diesel is now double what they mentioned.

 

[Bperry]

Those taylor test strips are junk as well. They go bad quite fast so maybe the first one was ok since it seemed to match sort of close to the borates I added when I first did so. But a few months later they had gone bad.

 

[JoyfulNoise]

Claim #4 (Protects HOCl from UV) is not proven. There is no chemical interaction between HOCl and borates and there is certainly no evidence that borates reduce UV extinction ... at least not any evidence I am aware of. The pH buffering effect can be highly variable from pool to pool with most north eastern pools (acidic, low alkalinity fill water and heavy rain dilution) not showing much benefit at all. The algaecidal properties of boron have been known for a long time but, at 50ppm recommended levels, it's weak at best. One would have to have borates above 200ppm to see significant results and that is not advisable from a health standpoint. Improved SWG efficiency comes mainly from the reduction in chlorine demand by lower algae levels and there is probably some mixed benefits from the fact that pH is buffered inside the cell when it is generating chlorine gas.

Robert Lowery was an interesting fellow and definitely able to capitalize on his experience as a pool industry professional as well as on the detailed chemistry knowledge of cyanurates that has been known since the 1970's but rarely talked about within the industry. Richard Falk (aka, @chem geek) did the DIY pool owner world a lot of good by making all of this chemistry information public knowledge AND for his work with the CDC on the updates to the Model Aquatic Health Code. It would be great to see more adoption of these techniques industry-wide but, like most changes, it's slower than molasses ...

 

[Mdragger88]

Those taylor test strips are junk as well. They go bad quite fast so maybe the first one was ok since it seemed to match sort of close to the borates I added when I first did so. But a few months later they had gone bad.

If you have zero borates they are exceptionally bad as the color doesn’t match anything.
I have had results that matched with expected levels with some level of borates in the water with newer & older strips.

 

[JoyfulNoise]

If you have zero borates they are exceptionally bad as the color doesn’t match anything.
I have had results that matched with expected levels with some level of borates in the water with newer & older strips.

The chemistry of these strips is such that they are trying to show a color change that is related to pH change (that's what the color indicator dye on the strip measures, pH). Chemicals are added to the strip to reduce the influence of cyanurates and carbonates so that it is only the borate level that is controlling the pH change. If there are no borates present, then the color change is going to be dominated by the other chemicals in the strip which will give a weird color result.

There's a better method for testing for borates that is linked to in my signature (see ).

 

[Mdragger88]

The chemistry of these strips is such that they are trying to show a color change that is related to pH change (that's what the color indicator dye on the strip measures, pH). Chemicals are added to the strip to reduce the influence of cyanurates and carbonates so that it is only the borate level that is controlling the pH change. If there are no borates present, then the color change is going to be dominated by the other chemicals in the strip which will give a weird color result.

There's a better method for testing for borates that is linked to in my signature (see ).

This makes sense.
They seem to always come out about as expected once I have the initial dose in from a fresh fill.
In my pool that’s not likely to occur (fresh fill) so I just test & replenish at the beginning of the season & let it ride. My ph really never moves in the pool so I don’t generally need to adjust it . I just add borates for all the other superficial reasons
in the hot tub I just confirm I got where I wanted/expected & let it ride until the next refill so I use maybe 3 strips a year. Not really worth buying more reagents/stuff that will expire before I could ever use them all.

 

[JoyfulNoise]

This makes sense.
They seem to always come out about as expected once I have the initial dose in from a fresh fill.
In my pool that’s not likely to occur (fresh fill) so I just test & replenish at the beginning of the season & let it ride. My ph really never moves in the pool so I don’t generally need to adjust it . I just add borates for all the other superficial reasons
in the hot tub I just confirm I got where I wanted/expected & let it ride until the next refill so I use maybe 3 strips a year. Not really worth buying more reagents/stuff that will expire before I could ever use them all.

I understand that. But just so you know, most of the reagents you already have in your pool test kit and the extra ones you would buy, bromothymol blue indicator and mannitol powder, are shelf-stable and will last forever .... just don't ingest the mannitol powder even though it tastes sweet because your gut bacteria will ferment it into hydrogen gas and methane gas ...

Fun-fact - Mannitol solutions were once studied for use as an easily tolerated bowel prep for colonoscopy procedures ... that was until some practitioners experience explosions from methane and hydrogen gas ignition during electrocautery removal of colonic polyps. I'm sure the surviving patients didn't appreciate dealing with the first degree burns down-under and the doctors were annoyed for having to wait several months for their eyebrows to grow back ...

 

[Bperry]

I dunno. I had ~30ppm and the first strip read about that. Then a couple months later the next strip (and all the rest would indicate much different results. Can’t remember but it was off the charts. I assumed the batch went bad.