Does Alginate Need Bottled Water
Water is water- Right? Not Necessarily.
Alginate is a combination of chemicals each included in the formula to do a certain thing. If your tap water has just a little of one or more chemicals (phosphates, chlorine, salts, calcium, etc.) then you could get "less than ideal" results. Problems take the form of lumpy mixing, long or short setting time and poor quality of the finished casting.
To ensure that you will get optimal results, please consider using inexpensive bottled water to mix with your alginate. Doesn't have to be Evian or "deionized", just store bought "spring water" should be sufficient.