pH meter ?

I can’t answer that yet. I have used for 2 batches with my house tap water but I don’t know the exact makeup of that water. I plan to go back to RO water for my next batch. Then I will have some insight.

My first batch with the meter was with RO water but the RO water had TDS of 70ppm and I think I messed up the calibration. That result was off from Brunwater but I have no idea what made up the 70 ppm of TDS.

PS. without a meter I did think just using Brunwater with RO water was helping my beer. But, I could never measure my pH. I wanted to know exactly where I was so I can try to correlate to what I am tasting with my lagers.