Dont think you can. except there are calculators online. I have kept 12% for 6 months - and noticed no difference in potency - but not measuredHe went from 289 to 370 with the addition of the oxydator. That's what I'm seeing. The point is it went up.
You all got me thinking again about the gallon of 12% I've got in my fridge. It's been in there for 6 months and I still have half left. How do you all generally determine if your peroxide is losing strength? A trending orp probe? The time in between refills? I see there are test strips available on Amazon.
