Tricky one - I would ring the formula company and ask for their advice. There are only a few brands of bottles water suitable for babies as they can have a high sodium content - and boiling the water to make the bottles could concentrate the minerals further.
Do you have one tap for drinking that isn't softened? I seem to remember a house I lived in had a softener but there was one tap that wasn't connected for drinking straight water. If you have an unsoftened source what about bying a cheap kettle just for water for the bottles?
Laura
