You are doing the test wrong.

Considering that the upper limit of the pH scale is 14 and that is pure lye or Draino and highly corrosive, you are clearly doing something wrong if you get a reading of 15+. If your water had a pH of 14, when you stuck your arm in it to measure, it would burn your skin right off.

I'm deadly serious--we are talking about pure Draino strength here.

If you checked the pH of the distilled water you would probably find it to have a pH of 7. Therefore, diluting it would not double the reading. Your diluter is already at 7.

pH goes from 1 (strongest acids) to 7 (neutral) to 14 (strongest bases or alkalines).

Dilution works for measuring chlorine and some other tests, but not pH.

I'm GUESSING that what you are doing could be like this: You get a reading past 8, off the scale. You dilute with distilled (let's assume its pH is 7 but you should measure it). Now let's assume your diluted reading is 7.6. You adjusted by doubling your reading (the spurious 15+ reading). I would adjust by doubling the part between 7--neutral and 7.6 (.6 becomes 1.2) and adding THAT to 7. That would give you a pH of 8.2 which is consistent with your first reading and won't burn your skin off.

I'm not saying my adjustment is correct or valid--Chem_Geek or someone else with equivalent chemistry skills could do that. But I'd bet my estimate is far closer than what you did.


In any case you need to add Muriatic Acid or Dry Acid to bring your pH down to the suggested range.