1.9 Domestic fresh and salt water systems The pump starters are controlled by pressure switches which operate when the pressure in the tank varies within predetermined limits as water is drawn off. Distilled water in now largely used in board; this may be corrosive ( due to the presence of dissolved co2)and flat to the taste. It is not unusual to provide for the introduction of certain chemicals, e.g. Calcium Chloride(Cacl2)and Sodium Bicarbonate(2NaHCO3)which, in solution are converted to Calcium Bicarbonate( Ca(hCo3 )2)and Sodium Chloride(2Naci)to render the water neutral and palatable. It may then be chlorinated to ensure bacteriological purity and subsequently de-chlorinated Figure 1. 9 shows such a system diagrammatically1.9 Domestic fresh and salt water systems • The pump starters are controlled by pressure switches which operate when the pressure in the tank varies within predetermined limits as water is drawn off. Distilled water in now largely used in board; this may be corrosive (due to the presence of dissolved CO2) and flat to the taste. It is not unusual to provide for the introduction of certain chemicals, e.g. Calcium Chloride (CaCl2) and Sodium Bicarbonate (2NaHCO3) which, in solution are converted to Calcium Bicarbonate (Ca(HCO3)2) and Sodium Chloride (2NaCl) to render the water neutral and palatable. It may then be chlorinated to ensure bacteriological purity and subsequently de-chlorinated. Figure 1.9 shows such a system diagrammatically