The Pros and Cons of Reverse Osmosis Water Filters
Reverse Osmosis systems have been around for quite a while. They are available in a variety of configurations and some feature pre-filtering to prolong the life of the membrane in the RO filter and some have a UV lamp to sterilise the water after it has been filtered.
The main advantage of RO filters is that they can desalinate water. This may not be of much use to most of us but for those who rely on bore water or who have very hard water, a reverse osmoosis system can remove the minerals causing the hardness leaving water that is easier to drink and easier for your body to absorb.
Since Reverse Osmosis water filters remove just about all minerals from the water some people use them to remove the fluoride from their drinking water. They will also remove chlorine from your drinking water.
It is often cost effective to install a reverse osmosis system to provide filtered water on a commercial scale rather than use other filtration or purification systems.
For domestic use, the smaller RO units can be very competitively priced.
The disadvantages of RO systems are that:
- they waste water – for every litre of filtered water you get out, you waste from 1 to 10 litres;
- they do not remove THMs unless combined with pre- or post-filtration;
- they are often s-l-o-w to produce pure water – how fast they operate depends on your mains water pressure;
- you need to store the water they produce until you are ready to use it;
- they usually remove all trace elements from your water even the beneficial minerals – some units have mineral filters that the water passes through to restore the beneficial minerals;
- they are not suitable for use on microbiologically unsafe water unless you purify it either before or after filtration;
- the membrane typically has to be replaced every 6 months or so depending on the particular RO system and the quality of your source water; and
- the will not remove foul tastes and odors.
If your source water is relatively clean and you are prepared to wait for your water to be filtered, a reverse osmosis system may be all you need. They will not remove pathogens from your water so you need to keep that in mind in situations where there may be some disruption to your water supply due to natural disasters, eg floods.
If you like the idea of having pure water instantly you are better off looking for a Point Of Use (POU) water filter or water purifier. Most of these have activated carbon as a component of the filter which means they can get rid of foul tastes and odors from the water. Having pure water on tap means you are much more likely to use it rather than using tap water. This has to be better for your health.
Thanks for the article. You raised some very interesting points. I had a Osmosis filter previously but it took too long to filter the water and the water bill was rather high so i got an activated carbon filtered water filter.