Hamster water..

There have been some studies on this in longer lived animals such as guinea pigs, which are frequently plagued by bladder stones. Filtered water is best to avoid problems with stones. As far as boiling water, if your tap water has problems that make it bad for humans, it would also be bad for your pets. In my area, the tap water will probably cause bladder stones eventually but it is drinkable as far as bacteria levels and all of that goes.

You should give your hamster spring water.