Borate threw my balance off

[JamesW]

There are several forms of the tetraborate compound.

Anhydrous sodium tetraborate. Na₂B₄O₇

Sodium tetraborate pentahydrate. Na₂B₄O₇•5H₂O

Sodium tetraborate decahydrate. Na₂B₄O₇•10H₂O

Borax is Sodium tetraborate decahydrate, which dissolves in water according to the following reaction.

Na₂B₄O₇·10H₂O --> 4B(OH)₃ + 2Na⁺ + 2OH^- + 3 H₂O

Sodium tetraborate pentahydrate is basically the same thing except with 5 water molecules attached instead of 10.

Na₂B₄O₇·5H₂O + 2H₂O --> 4B(OH)₃ + 2Na⁺ + 2OH^-

The net result on the pH and TA is basically like adding 2 moles of sodium hydroxide per mole of Borax.

Adding 47.6 lb of Borax is equivalent to adding about 10 lb of sodium hydroxide.

 

[PoolStored]

Found a thread that talks about this exact thing. Almost identical result. The recommendation here is to just add acid to whenever the pH goes up, and over time the alkalinity will come back down. Do you agree?

Proteam Supreme Plus raised TA

Hi there and thanks in advance for reading and commenting on this post. Reading all of the positive impacts from having borates in the pool, I decided to add the Proteam Supreme Plus to get to 50 ppm. I know this is a more expensive route, but I was looking for easy and this solution would...

www.troublefreepool.com

The easiest/cheapest way I found to reduce high TA is to reduce pH with Muriatic to about 7.0. (CO2 outgas is highest from 7.0 to 7.2). This will also reduce TA. Then I aerate to raise pH back to 7.4, then repeat. Reduced TA from 140 to 70 in about 3 days with this method. This is what I built and put it on top of a sump pump in the shallow end (see post #4) --> DIY Aerator The "Trick" is to make LOTS of small bubbles. I can reduce TA 10 points in 12 hours in my 31K gallon pool, and it's a kinda fun water feature...kids love it).