Hi,

I'm in Spain where the tap water is very chlorinated and has lots of
calcium in it (and probably lots of other, less noticeable things), so
for tea making bottled water is used.

I'm wondering what to look out for in bottled water, all the bottles
here have to have a breakdown of calcium, chlorine, sodium etc on their
label so it is easy to tell what's in them.

Is calcium quantity one of the main things to look for (I think I read
this somewhere, but never had it confirmed)?

Two of the big makers of water here have dramatically different calcium
levels in their water, one being 5mg/l, the other being more like
35mg/l. The much cheaper bottles have higher amounts still. What is a
good amount to have? Can there be too little?

Any help, or other tips about what to look for in bottled water to make
a good brew would be much appreciated.