Deep in Central CA there is mysterious Adobe Springs, where pure MgHCO3 water bubbles up. rare & costly, so I make my own . Take 1 tbsp MgOH 500mg drop into a fresh liter of Soda Water recap swirl wait til clear. Makes 500mg MgHCO3. Divide into 4 or 3 liter bottles then bring up with drinking water. 125 to 167mg MgHCO3/l very nice on ice, swirl to structure the clusters. rda 1 to 2mg/lb body weigh/day?