Softened water is perfectly safe to drink. Its is a common misconception that softened water is unsafe to drink, this is because softening water slightly increases the amount of sodium in the water. Typically a glass of softened water will contain about 50mg of sodium. To put this in perspective, a slice of brown bread contains around 200mg and there is more sodium in a glass of milk than in a glass of softened water. The only times we advise against drinking softened water is when making up formula for small babies or if you are on a prescribed low sodium diet.