When I use 20 mule borax and acid, what else is produced.

Have you considered granular boric acid instead? It's much easier to add than borax & MA.
I may yet buy a pail for next year now that it's on Amazon free delivery. It should keep. BTW, 60 lbs for a skinny Amazon delivery person is a bit much.
I'm doing my pool now, and I only had to go to from 30 ppm. And we use 20 MT washing clothes as a detergent booster. (Alkalinity helps). But I may buy a pail from ChinaZon, just to boost DUDA in the hopes they will keep doing it.
Now about that missing third component...
 
Borax dissolves as boric acid into water:

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

The 2OH- are what raise pH in the process.

Boric acid is then in a pH-dependant equilibrium with borate ion:

B(OH)3 + H2O <--> B(OH)4- + H+

Adding muriatic acid will simply decrease pH, moving above equilibrium a little bit to the left, basically turning some borate ion into boric acid. But at pool pH, boric acid is the dominant species anyway:

Screenshot_20240502-201011.png

There is no by-product from the neutralisation. The hydrogen ion from the muriatic acid addition simply neutralises the hydroxyl ion from the Borax addition, decreasing pH which makes all chemical equilibriums rejig a bit, not just above equilibrium between boric acid and borate ion (carbonates, CYA, chlorine, whatever is in the water)
 
  • Like
Reactions: Chuckiechan
You could probably say that the by-product from adding borates via Borax and muriatic acid instead of straight boric acid is salt.

Borax adds sodium ions, and muriatic acid adds chloride, that you both wouldn't add by adding plain boric acid.
 
  • Like
Reactions: Chuckiechan
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.