What to consider when buying Water Filter or Purification System?

There are so many brands and types of Water Filter or Purification System in the market. Some can be bought from retail stores, some are sold online or by MLM system.

 A simple guide.

Filter Standard / Quality
Ensure the Filter System or Dispenser have NSF 53 Standard Certified - NSF 53 Standard -> Health Effects ( reduce specific health-related contaminants )

Some filters in the market only have NSF 42 Standard, which is only for as Aesthetic purpose

You can read up here
http://www.nsf.org/services/by-industry/water-wastewater/residential-water-treatment/residential-drinking-water-treatment-standards

Filter Types
Some brands indicated 3 stages filter systems, so need 3 filters.
Do note, more filters equal to more cost, each filter is about S$120 or more.
Do not be fool by the number of filtration stages, or the number of filters.
Having more filters do not meant filter is better. 1 filter can also be 3 stages filtration system.

Types you can consider
Below Sink Filter connect to main tap
Below Sink Filter connect to separate tap
Tabletop Dispenser

This depends on individual preference.