In this video, Adrian compares various brands of bottled water against distilled water made using a water distiller, using an electrolyzer to reveal the impurities of each.

"Just in case you thought bottled waters were good to drink and distilled water is just unnecessary I thought it would be interesting to do some electrolysis on the water.

How accurate this is I do not know, yet the results are fast and very visual. I compare distilled water, welsh tap water and 8 bottled waters, and then at the end I takes all the water left in the bottles we examined and distil that and do a final electrolysis of the distilled water from that to see if it gets cleaned up."