Very rightly said in your para about water. Unlike the domestic RO systems, the packaged drinking water quality is strictly monitored by the B.I.S. where just the TDS is not an important factor, but also the PH & almost every packaged drinking water is re-mineraised with added-minerals, to make it suitable to the body. And moreover, the wastage water from an Industrial RO unit , if designed rightly is also in the range of just 30 % compared to 50-60% in the domestic (if not more).