Your water company on request should be able to give you a complete run down on whats in your water.... i recently fell foul as my water company switched resevoirs.... the new resevoire was 150miles away from the previouse and was lacking in sulphur, iron, boron....
your local aquatics center will be able to test the following
total disolved solids-TDS
CARBONATE HARDNESS(MIX OF MAGNESIUM CARBONATE AND CALCIUM CARBONATE I THINK)
You can order these straight of the old WWW.
Nutrafin Master Test Kit