Ice should be constructed and deployed with the same consideration you'd give to any other beverage ingredient. I explained why, and how, on NPR the other day. Click through to hear and read the segment.
Water is H2O. When you add CO2 it produces carbonic acid, which accounts for seltzer's taste. At first I thought that made it something other than water, because it's not simply H2O anymore. But by that logic flavored water isn't water either. So what do you think?