Sodium Content of Water-Softened Water

To the Editor.— Physicians are ever alert to problems of excess salt ingestion in patients with congestive heart failure. Sodium chloride is used to regenerate the synthetic ion-exchange resin in home water-softeners. The question often arises whether the sodium chloride so used can lead to a high sodium content in the water. Separate analysis of such water and normal tap water by flame photometer reveals that there are 8.5 mEq of sodium per liter in the water-softened water as opposed to no sodium in the ion-softened water. If the patient would drink one liter of water-softened water, he would be ingesting approximately 500 mg of sodium chloride. This is certainly a small amount but, needless to say, enough that the physician should consider it in the management of patients with intractable congestive heart failure.