one last comment, in short the reason why mineral water is not sutible as actually because it contains TOO MANY minerals for an infant. This leads to problems with osmoregualtion, and ironically water poisoning, which will induce seizures.
Tap water, has all minerals stripped out and only chlorine and fluroide added, boiling removes the chlorine, and the fluroide is in safe concentrations.

You have had your health advisor, information from the british government, and me, a biologist give you informed advice.
Wake up!