RO purifier’s misery

According to the World Health Organization (WHO), if the presence of Total Dissolved Salts (TDS) is between 300 to 600 mg/L in drinking water then it is ‘Good’. Even the Bureau of Indian Standards (BIS) says that if the TDS is less than 500 mg/L in drinking water, it is acceptable to drink.

Reverse Osmosis (RO) in developed countries used only for desalination (producing drinking water from high TDS seawater or brackish water). It is also used when borewell/groundwater is being used. In India, RO companies to increase their sales they are misinforming the customers.

Disadvantages of RO purifier:

1. It rejects Magnesium and Calcium, which are very important salts for the body. Prolonged use might cause health impacts due to a lack of salts.
2. 70 to 80%  of water is wasted during the purification process (4 litres of water is wasted for 1 litre filtered water).
3. The wastewater is highly saline cannot be used to flush toilets or wash the car as metal parts would corrode. Eventually, it will make its way to drain and there is a high probability that it would corrode the drainage system.

In the recent National Green Tribunal order it is mandated that RO purifiers must be banned when drinking water TDS is less than 500 mg/L. And also Local Municipalities should share details of TDS (they provide) in the water bill.

Last time when I checked TDS in my home, it was 205 mg/L (water was supplied by Municipal corporation). In urban cities, due to poor infrastructure drinking water is contaminated by sewage which causes many water-borne diseases. It is advisable to use Ultrafiltration (UF) membranes as they can remove over 99.9% of bacteria, Giardia and viruses (fig 1) when the TDS is below 500 mg/L.

First step while choosing the filter system for your house would be to check TDS of municipal water and ground water and decide the type of filter. You can request a free demo from any of the Water Purifier companies to check TDS for your home(don’t hesitate!).