Start with a water report
You need calcium, magnesium, sodium, chloride, sulfate and bicarbonate in mg/L. Total hardness or water pH alone cannot define a treatment plan. Record the analysis source and date: supplier values can vary.
Minerals versus alkalinity
Chloride and sulfate influence flavour. Calcium and magnesium also affect the mash. Bicarbonate contributes to alkalinity, the capacity to neutralise acid. Bicarbonate in mg/L differs from alkalinity as CaCO₃: approximately, alkalinity as CaCO₃ = HCO₃ × 50 / 61.
Choose a suitable treatment
Blend with suitable RO or distilled water when several minerals are excessive. Acid can be suitable when alkalinity is the main concern. Acidulated malt acts in the mash. Salts add minerals; they cannot selectively remove existing ions. Treat the proposed profile as a guide rather than an exact target at any cost.
Can I boil the water?
Boiling can precipitate calcium carbonate in water with suitable temporary hardness. Let it settle and decant the clear water. Both alkalinity and calcium change, and not all salts disappear. The remaining profile is uncertain without analysis, so this calculator does not invent post-boiling values.
A practical sequence
Check the report → select treatment → blend if needed → calculate mineral additions → treat alkalinity → measure mash pH in a cooled sample. Mash and sparge water have separate volumes. Calculated values and assumptions help plan; measurements verify what happened on brew day.