Here is why RO water is bad for health:
http://ezinearticles.com/?The-Truth-About-..alth&id=1423174
There are two negative things that happen when you drink demineralized water. Because demineralized water contains more hydrogen, it is an acid with a pH level below 7. The first negative thing that happens is that when we drink an acid, our bodies pull minerals from our bones and teeth to produce bicarbonate, which neutralizes the acid. The second negative result is that our bodies produce more free radicals when we are in an acid state versus an alkaline one. That leads to an increased risk of cancer! I don't know about you but if drinking water purified by a reverse osmosis water unit has been linked to cancer, I am not willing to take the risk!
http://www.snyderhealth.com/water_ionizers..osis_water.html
Early Death Comes From Drinking Distilled/RO Water
.. Disease and early death is more likely to be seen with the long term drinking of distilled water. Avoid it except in special circumstances.