Why we need to purify the water in our home?
To remove micro-organisms that cause illness.
To remove unhealthy chemicals
To remove the bad odour
To remove the turbidity due to dissolved dirt
What should your water filter do?
It should remove the micro organisms, unhealthy chemicals, bad odour, and turbidity.
But at the same time it should not remove or disturb the healthy salts present in water. These salts are necessary for our well being and healthy body.
Now you are ready to choose your water filter!
What features of various brands available in market do what work?
Ultraviolet exposure to water (useless feature) : There are water filters in the market that boast that they have a facility that exposes the water flow under ultraviolet lamp for 15-20 seconds. Well be aware that the water in the river, sea, and tanks is exposed to sun’s ultraviolet light throughout the day. Hence, the water is already well treated with ultraviolet rays. Even if it is not, and the water filter boasts of exposing the water under ultraviolet light for few seconds, the process does not kill 100 percent of the germs, it just deactivates them for few minutes and they become active again.
Reverse Osmosis (hazardous to health): Reverse Osmosis or popularily called "RO" is a very dangerous feature. It takes away almost ALL the salts, dirt, chemicals, organisms, etc from the water making it 100% free form salts, and 100% pure form of water. The worst part is that it takes away even the essential salts that are necessary for our body and for which there is need to drink water. If you will get habituated to RO water, you will be prone to sickness and the body will develop dificiency in minerals.
Active carbon (good feature): Active Carbon sometimes comes coated with silver. The purpose of active carbon is to remove the bad odor from the water. This is present in almost all the water filters.
Filtering membrane, candle, fibre, etc. (good feature): The purpose of these is to filter away the dissolved solids (salts, chemicals, organisms, etc). This is just like a simple obstruction having minute pores through which the water passes, leaving the larger sized particles and allowing clean water to flow. It depends on how small the membrane is. If it is not too small, it will allow the organisms and salts to pass through. If it is too small, it will remove the useful minerals also.
What should be the size of this membrane?
The membrane / candle should be at leat 0.01 micron size because the smallest virus is 0.02 micron. This size removes all the harmful bacteria, etc. but retains the essential salts.
Which water filter from the market is good?
KENT: Kent water filters that work on RO technology , and hence, are harmful to health because they remove even the essential solids. They realised their mistake and then introduced a new model that first purifies the water then gives you a choice to mix dirty water to recover some lost essential minerals. This is as good as drinking dirty water even after paying Rs. 14, 000 (cost of their water filter). As their spares are all from UK, servicing this machine is also very costly affair.
AQUAGARD: They are fooling the public with their UV technology. This water filter does not make the water 100 percent safe. Requires electricity for operation.
PERMIONICS: Not so popular company from Vadodara. Has 0.10 mm thich membrane. This size does not filter all the bacteria.
DOLPHIN: Best of all. Has 0.01 membrane and clears all bacteria. Retains essential minerals. This is a new company and is operating under low budget, hence, you may not see their advertisements too often. The only negative point of this filter is its bulky design. The servicing is also very easy. The filter has ultrafilteration membrane cartridge using the patented technology of BARC, Mumbai. It will take some time for this filter to reach other parts of the country. Its available in Mumbai and Maharashtra currently. The unit does not require electricity for operation.