Regarding the copper, that is suggested in Ayurveda as a cleansing and possibly anti-fungal/bacteria and digestion boost. I find it way too strong as it aggravates Pitta probably due to some sort of acidity issue.
Regarding the rock, nothing scientific, as I had seen it previously in a earlier version of the water purifier. It was very expensive so I thought I would try my own version of it.
I have no idea what effects various rocks have on water, but I suspect somebody somewhere may.
I too like carbonated mineral water. The carbonation pacifies pitta.
If you know the Jyotish recommendation of the stones/gems which are appropo for you, then put them in the water container.
The Santevia system tastes good. I have no idea if it is scientifically proven for anything.
I remember years ago when I was visiting my friend who is a Vaidya, (Ayurvedic doctor) he invited me to go to see someone who was selling a filter system similar to the one I eventually bought. (He needed a drive and I had a car) The person selling it had assembled a group of people who were using the filter. These people all sincerely said that the water was like a Godsend. They were suffering from various serious illnesses and had experienced almost miracle cures from using the water. These people were not going to gain financially from lying as there were too many.
Te system uses
ceramic prefilter same idea as a wine filter
activated cocnut carbon charcoal
natural silica sand
volcanic zeolite mineral granules
highly porous maifan stones
Bio-ceramic energy balls
mineral stones
and a spout with a magnet in it.