My home is fed by a private well. the pH of my well water is already fairly low in pH, 6.4. We have a water softener and just recently tested the water at our tap and the pH was 6.1. We have our water going thru an RO system before we drink it but it seems to taste a bit "metallicy" and seems to be a bit acidic (obvisouly why).

I am there any small device/filter/treatment/etc that I could deploy under my sink (next to my RO system) that would increase the pH of my water to more near 7 ?

THanks for any help !