You are correct. You don't need a certain weight to measure the PH. Also, the PH of 1 g of solution will be the same as the PH of 100 g of solution.
However, the weight of 100 ml of solution will vary according to the strength of sodium chlorite.
For example, 100 ml will weigh:
102 g for a 3% solution
104 g for a 5% solution
122 g for a 22% solution, which is what Miracle-Mineral-Supplement
So, we are actually looking at two different things.
One is taking a measurement of what the PH of the solution is. And the other is checking the weight of 100 ml of solution.
They are loosely, but not directly related.
I checked my Miracle-Mineral-Supplement
solution and found that 100 ml weights 122 g, AND the solution has a PH of 13
I also checked a 5% Stabilized Chlorine Dioxide solution and found that 100 ml weights 104 g, AND it has a PH of 11.
So, if your PH meter is accurate, and you are getting a PH of 11 from a sample of Miracle-Mineral-Supplement
solution, I believe Jim Humble is saying that he is pretty confident that 100 ml of that solution will not weigh 122 g.
On the other hand, if 100 ml of your sample solution weights 122 g, then your meter is out of calibration.
I hope you see that weight does not effect your ability to take a PH measurement, but does have an effect on the concentration of the sodium chlorite.
Now, does that help clear the water, or did I just muddy it up more... [smile icon]