3 Things You Should Know Before Purchasing a Water Filter


Buying a home water filter can be a confusing and expensive proposition, so it’s important that you choose the right system for your home. Different methods of water filtration specialize in different things, and it’s crucial you get the water filter that works best for your water supply.


Find out as much as possible about your water supply.

You need to know specifically what is contaminating your water before you decide how to combat the problem. Your local government, council, or water provider can help you with this, and can provide you with a water survey.

You should be particularly wary if you live in, or near an industrial area, or if your neighborhood has an old plumbing infrastructure (Lead was only banned as a material used in water pipe making in 1986). Water can be contaminated on its journey from the water treatment plant to your home. Some common causes of pollution are sewage leaks, chemicals used in farming, manufacturing processes, and malfunctioning water treatment systems like septic tanks.

A water quality assessment should involve samples taken from numerous places, all served by the same water pipes. Water quality assessment kits can be bought online, and independent, professional laboratories offer this service too. Even just talking to your neighbors might reveal a lot about the water quality history in your area. They might even have some great advice about filters.


Choose your filter type based on your water composition and your needs.

If your water is badly polluted then a reverse osmosis system  is the most effective method of filtration. It can filter down to 0.0001 microns (0.00000001 cm), which will remove virtually all contaminants. However, it must be installed at the point of use (usually under the kitchen sink) and will only filter the water at one point in your home. If you want all of your household water filtered (drinking, cooking, bathing etc) then you will need a whole house water filter system. These systems will filter down to 0.35 microns at the most (but usually 1 or 5) so are not as effective as their reverse osmosis counterparts. For a home badly affected by water pollution then a whole house water filter combined with reverse osmosis system is your most effective (and expensive) weapon. Below are some common water contaminants and their sizes in microns.

  • Bacteria 0.3 – 60 microns (1 micron = 0.0001 Centimeters)
  • Lead 0.1 – 0.7 microns
  • Pesticides & Herbicides 0.001 microns
  • Viruses 0.005 – 0.3 microns
  • Coal Dust 1- 100 microns
  • Insecticides 0.5 – 10 microns

This information illustrates the point about different filters for different problems with your water. For example, if you were to live in the countryside and have a problem with pesticides contaminating your water, then the only effective filter would be a reverse osmosis one.


Be aware of the life cycle and replacement cost of filters

While some water filters may seem initially expensive, you should really judge their cost on how often you will need to change the filters, and the filter cost. A system that is $200 dollars more expensive, but only requires filter changes every year, may well work out at being a lot cheaper over the course of 10 years. So don’t be deceived by the initial price of the water filter system. The slightly pricier models will often work out at being more efficient, and use longer life filters. This can make them a whole lot cheaper in the long run.

The true cost of a water filter system should take into account the initial cost (installation ?), the filter costs, filter lifespans, and any waste water or extra utility fees. I would estimate a figure for a 5 or 10 year period to give a more accurate reflection of a water filter system’s cost.


The author is a teacher, and founder of waterfilteranswers.com, a website that offers advice and reviews of water filters, besides informative articles about water pollution.