I would guess it would really depend on what is in the well water. Do you have an analysis of what is in it? I know my friend's family has high level of arsenic in their well water. I wouldn't want to use that.
For most marine setups R/O water is generally advised or distilled as it contains practically nothing.
I’m thinking at Home Depot they sell a test that you mail in for $19.99. I would get 2 of the tests and test both tap and well. This way you will see what’s in your water and witch one you will be drinking out of.