water adjustments

[baphomite51]

im gonna start dabbling in water chemistry, my plan is to buy bottled water and plug the numbers provided on the bottle into beersmith and use the 'calculate best additions' tool to match a paticular water profile like burton water for example, is there any issue with doing this is the beersmith tool good? is the info provided on bottled water accurate? and should i be careful about adding any paticular additives like chalk? is there any kind of guidlines so i dont add too much and end up with chalky beer or what have you?