Here is a Science fair project presented by a girl in a secondary school in Sussex . In it she took filtered water and divided it into two parts. The first part she heated to boiling in a pan on the stove, and the second part she heated to boiling in a microwave. Then after cooling she used the water to water two identical plants to see if there would be any difference in the growth between the plants
Found this on Facebook, not sure how to show it here but go to link & scroll down to bottom of page you will see 2 plantsin a pic- click on these to see the results.