Board Defense

[Finally]

I am about to refill my pool, so I picked up a 50 lb bag of boric acid at a local industrial chemical supply company (for $50) and a very friendly manager there was curious what I was using it for. When I explained it was to add borates to my pool, he was really interested and mentioned a product they carry called "Board Defense" that is 98% disodium octaborate tetrahydrate (basically the same chemical as in PoolProof, but much higher concentration).

He said it is a bit more than twice the cost per pound as boric acid, but that it would add a lot more borates and is completely water soluble, as well as having a pH of about 7.8 (which supposedly would negate the need to add acid).

Anyone researched this before, or have any idea what quantities of this product would be needed vs. what is needed for boric acid? This product is basically a concentrated wood pesticide, fungicide, and termiticide, so it sounds a little scary to add to a pool, especially without knowing exactly what quantity would be needed.

 

[Arizonarob]

Hang tight,and I know someone, that knows someone, that knows someone, that can help ya out.
@JoyfulNoise

 

[JoyfulNoise]

It will raise your pH higher than 7.8 for sure and you will definitely need acid with that. It doesn’t add anymore borates than what you would do by using boric acid.

Boric acid is a weak acid that will only slightly lower pH.

All other oxyoboron salts are strong bases. They raise pH very strongly.

Use boric acid.

 

[Finally]

Thanks for the info. I was still planning on using the boric acid but just was curious after what this guy said about it

 

[Donldson]

On the pesticide question, don't worry about it. Borates are commonly used for that purpose. The ant killer TERRO is just sugar water with borax mixed in. It's not an instant poison, takes time to build up and work its magic, which is why it's great for ants to take back and share with the whole colony.

 

[JamesW]

For 50 ppm borates in a 10,000 gallon pool, you would need 589 oz of Borax or 318 oz disodium octaborate tetrahydrate or 382 oz boric acid.

The octaborate has twice the boron atoms as tetraborate. Octa = 8. Tetra =4.

 

[JoyfulNoise]

So your adding about 27% less octoborate by weight as compared to the boric acid BUT you would pay roughly twice as much for it from the supplier .....therefore boric acid is the more cost-effective choice especially considering you would need to add muriatic acid to compensate for the pH rise induced by the octoborate.

 

[Teald024]

Octoborate.... sounds like a great superhero villain name.

 

[JamesW]

There was a woman called Octomom who had octuplets. Some portrayed her as a villain. But, maybe she was a hero after all.