Is there an advantage of using bottled spring water over tap water? Where can I find more info on this?

The main problem with most tap waters is that they are doctored up for people's health - and plants are not people even if gven names and lots of love and attention. The big offenders are clorination and the addition of fluoride. Both can have bad effects on plant health. You can read about this by entering 'water quality for plants' on a search engine. You will get many thousands of sites offeed, and picking the right one will fill the long winter evenings - but the answers are all there. On the other hand, be sure that the bottled spring watere that you use has not simply come from a tap into a fancy bottle ...Derek