Can I get by just removing calcium and magnesium with water softeners?
‘ Hard’ water contains high levels of calcium and magnesium left as white deposits after water evaporates. In home water softening systems, the calcium and magnesium are replaced with sodium to avoid clogging of pipes and water heaters, unsightly deposits of ‘lime scale’ and to help soap and detergents dissolve. Iron may also be removed with the proper softeners. Water softening is basically an ion exchange process in which the calcium and magnesium ions are exchanged for either sodium or potassium ions (NaCl or KCl). Most home units use sodium and are not appropriate for greenhouse use. Softening systems using potassium can be used, however. Water softeners will not reduce the EC, but the potassium added by the softener can be subtracted from the amount of fertilizer potassium added. Removing the calcium and magnesium also avoids competition with potassium. However the plant will still need recommended levels of calcium and magnesium for good growth. What about the other types of wate
