What did you learn from this lab about water and about process?

I learned that "purified water" is not as pure as I thought it was. I never gave much thought to, or realized, that there are many other things in my water other than the components that create water. By doing this lab, I realized that there are various ions in each source of water on this earth, and unless the water is distilled, they are not completely removed from the water systems. I also learned that in order to test for the presence or absence of ions in different solutions, it is necessary to go through tedious processes that require much focus and observation. Testing water was definitely not as easy as I thought it would be!