All living beings on earth whether plant kingdom  or animal kingdom they all  contain water. All animals, living beings including plants  are nothing but our ancestors. Infact we share most of their genes. We humans are made up of 72% water and our brain is made up of 89% water. All the livings beings maintain water pH close to neutral which is 7.5.

The human blood pH is tightly regulated between 7.35 and 7.45. Rain water TDS ( Total dissolved salts)  is close to zero _ 0 and pH is between 5.6 to 5.9 , if the pH of rain water is less than 5.6 then it’s acid rain.

What happens to plants when it rains _ Plants cannot directly absorb the nutrients from the soil_ rain water is acidic when it feels the soil it absorbs the nutrients and takes it to the roots of the plants and trees. 
For we humans too the water is good if it’s TDS is to the lowest ( similar to rain water) and  pH between 6.5 to 8.5 .  Infact low TDS and slightly low pH water  helps to absorb the nutrients from the food we eat and quickly transfer it to blood which is done by our intestines. 

90% of life  thrives in the equatorial region  and all animals in savanaa drink water stored in small reservoirs which is nothing but stored rain water with pH less than neutral and TDS less than 200ppm. As said rain water TDS is zero when it touches the ground it abdorbs  the nutrients from the soil and the TDS is increased suddenly as rain water is so vibrant to absorb minerals as rain water does not have any mineralls in it.  
Nature our teacher. Reverse Osmosis ( RO) is nothing but reverse engineering to remove the salts from the water and give us the pure water so when we drink it flushes out the  accumulated salts  in our cells and pushes out as urine. Ex. If a person stranded in sea if he drinks sea water he will die fast because he is pushing more salts into his blood. RO water has less TDS  quenching our thirst much faster. 

More over our brain makes our tongue to taste good only the water which has less salts , so just listen to your brain and drink RO water without any second thought. You get minerals only  from your food and water is just a medium inside your body.

Also do not drink alkaline water –  Already our stomach produces acid to extract the nutrients from the food we eat , if we drink alkaline water it neutralizes the pH level in stomach ( in fact stomach juices  should be always acidic) and nutrients will not absorbed and we may also face indigestion problems. 

There is no proof our body takes minerals only from drinking water.

1. Siruvani water contain calcium less than 5 ppm but still kovai people are healthy and strong and kovai known for heavy engineering industries.
2. The hen drinks less than 50 ml water daily but able to produce the egg daily and the egg shell contains more than 700 ppm of calcium
So if anybody argues RO water got less minerals tell them we make our own calcium and less stones in the kidney.v