water adjustment is quite cheap - I keep "mineral water" on tap at home. it's a mixture of gypsum, calcium carbonate and epsom salt, conveniently pre-packaged

water adjustment is quite cheap - I keep "mineral water" on tap at home. it's a mixture of gypsum, calcium carbonate and epsom salt, conveniently pre-packaged as Burton salts. I use 1/4tsp per gallon of distilled water. the expensive part is the distilled water (even more-so than the co2 used to carbonate it).