Having read much about water quality issues, we would recommend drinking only filtered or purified water.
With so many brands on the market it can be confusing knowing which one to buy and, while having a water filter is much better than having none, it is important that you are aware of the contaminants that the filter removes - and more importantly the contaminants that the filter leaves in your water. Thus it is in your best interests to acquaint yourself with the effectiveness of any water purifier before you purchase it.
Most water filters will remove cysts such as giardia and cryptosporidia and many will also remove chlorine and odours. However, not all will remove heavy metals such as lead, mercury and cadmium, chemicals such as pesticides and fertilisers which leach in to the water supply, or bacteria and viruses. It all depends on the filter or purifier technology.
Some purifiers use an ultraviolet (UV) light to sterilise the water (e.g., the Amway eSpring). While UV is a disinfectant it suffers from four main disadvantages.
- It requires the water to be as clear as possible for the UV to be effective.
- It requires time to work, i.e., the water has to be exposed to the UV light for a sufficient time to kill off the pathogens.
- It requires electricity to operate.
- The UV light is another component to have to replace.
In many cases, the filters are intended to operate only on microbiologically safe water. This often limits using them for tank or bore water unless the water has been tested and found to be safe. Even then, droppings from bird or possums can contaminate and otherwise safe water tank and render the water somewhat suspect.
For your convenience, the water filter comparison has been prepared as a one page PDF document. You will need the Acrobat reader in order to view it. As far as possible all data has been taken from the manufacturer's website or product manual. A question mark ("?") in the column indicates that no information could be found for that contaminant - in most cases that means the contaminant is not removed by the filter. A removal efficiency of 95% was accepted as the basis of reasonable filtration efficacy; however, I believe a good filter or purifier should remove at least 99% of any contaminant.
- Water Filter Main Feature Comparison (you can save this to your computer by right-clicking and choosing Save Link As... or Save Target As...)