Reverse osmosis water vs. charcoal flter with .5 micron

I guess the answer begs the question…what’s your beginning water chemistry before its filtered? With municipal water…particularly in my area, the water changes occasionally…sometimes pH, PPM, and chlorine content. I havent had it tested but i know if I was to test it say quarterly, it would be a bit different each time.

What would you prefer? RO or Charcoal?

Another question…if you used RO water but wanted to add back only one “prescribed” chemical additive for a decent range of beer styles to benefit them all…what would it be?

RO water plus gypsum is the base of pretty much everything I brew. A little chloride is good too, but you said only one.

Carbon filtration does not change the ionic content of the water. It only removes hypochlorite and chloramine compounds along with organic compounds. Things like Ca, Cl, and SO4 go right through, unaffected.

If your water has low ionic content, then it is possible that a carbon filter is all you need to ‘polish’ your water for brewing. If the water has high ionic content, then RO is a very good option for reducing that content. RO typically includes particulate and carbon pre-filters, so it would do everything that the carbon filter does…and more.