Now we subtract two from 14 and we get a PH of twelve. That means our PH increases by five increments. That's equivalent to a 100,000 fold increase in the hydroxide concentration. That's a very big increase in PH. So the takeaway from this is that adding a small amount of acid or base to pure water will drastically change the PH of water. Now, if you're confused about how we got this part or this part, check out the link below.