I use tap water since our water is relatively low in everything except sodium and alkalinity. Basically I have to acidify for most beers, and a lot for pale beers. I use phosphoric. I then add brewing salts appropriate for the style.
pH 8.5
Sodium, Na 79
Potassium, K 2
Calcium, Ca 3
Magnesium, Mg < 1
Total Hardness, CaCO3 12
Nitrate, NO3-N < 0.1 (SAFE)
Sulfate, SO4-S 2
Chloride, Cl 17
Carbonate, CO3 9
Bicarbonate, HCO3 191
Total Alkalinity, CaCO3 172
Total Phosphorus, P 0.62
Total Iron, Fe < 0.01