Which is the best water purifying technology? You cannot decide on the best water purifying technology without knowing the quality of water that you receive. If the water is of good quality and free of TDS or microbes, even a simple gravitational filter will do the job for you. For high TDS, RO water is the best solution and if you wish to kill all the microbes in the water, you should go for UV treatment. All these technologies can be combined in one machine, if required, to get the best water purifier filter.
You must not use RO water filters if your water already has low TDS value as it would make it even lower and become harmful for the human body. Even with the other methods of purification, you must exercise caution and should not use them if not required.
Considering the worst case scenario, where the water is dirty with high TDS and microbial impurities, a combination of UF+RO+UV will be the best to combat all the impurities. For more details click on- ​RO Water