What Types Of Home Water Filters Are Available To You Today?
Do you know how many types of home water filtration systems there are? Does it even matter? Beyond the issue of curiosity, it is always better to know the limitations of your home water filter based on the different technologies used. It's rather like buying a car. A standard 4-cylinder engine is the most fuel efficient, a V6 is more powerful, a rotary engine is smoother and more reliable but less fuel efficient, a diesel engine is cheaper and you can also potentially make your own biodiesel when oil becomes scarce and expensive. There is a similar principle at work with home water filters.
We'll start with the simple muslin cloth. It is basically a DIY water filter. It is extremely cheap - you can buy a year's supply for just a few dollars. All you need to do is wrap one or more layers of muslin cloth around the mouth of your tap and you have an instant water filter. There is one big glaring problem - it only removes coarse sediment from your drinking water. It does not remove chlorine or any other chemical and it does not remove fine sediment. It also looks ugly. But did we mention that it is extremely cheap?
The next step up are sediment filters made from polyester fiber, cotton or some other cellulose fiber. These are also cheap - you can buy one for under $10. The replacement water filter cartridges cost less than $5. And unlike muslin, these sediment filters can remove fine sediment. However, like muslin, they do not remove chlorine, chemicals and heavy metals. You also may not be able to find them in department stores. Amazon also does not sell these types of filters, so you will need to use Google or Bing to search for online dealers who carry them. DIY-ers can also make their own sediment water filters.
A better grade of sediment filter is made from ceramic. In fact, some ceramic filters are so good (they are rated at 0.5 micron to 0.1 micron) that they can even remove cysts from your tap water. In their heydays, they were also quite cheap. However, it is rather hard to find them in stores nowadays. Like the polyester sediment filters, you may need to look for dealers of this type of home water filter using Google or Bing.
The next group of home water filters we are going to look at are carbon water filtration systems. These drinking water filtration systems use blocks of activated carbon with numerous microscopic pores to remove sediment and adsorb chlorine as well as organic poisons (e.g. modern herbicides and pesticides made from oil). At the low end you will find 50 micron drinking water purifiers selling for under $50 (like the Culligan faucet water filters). At the high end you will find 0.5 micron home drinking water filters selling for hundreds of dollars. Some of the best of this type of home water filter (e.g. Everpure H-300 or Aquasana water filter) produce water that tastes as good as any bottled drinking water. On the downside, these purely carbon home water filtration systems do not remove heavy metals (like lead, copper and mercury) or nitrites and nitrates (in fertilizer).
One special type of home drinking water filters are the resin ion exchange units. These units contain special chemicals embedded in a resin matrix. They are specially designed to remove specific contaminants like lead, mercury or nitrites/nitrates. The problem is that they are not able to remove all heavy metals. For example, an ion exchange system that is rated to remove lead will only remove lead. An ion exchange rated for mercury only removes mercury. Of course, high-end units can remove combinations of contaminants. One common combination is lead and nitrites/nitrates. Resin ion exchange units normally come as part of a carbon drinking water filtration system.
The last type of home water filters we will look at are reverse osmosis water purification systems. These drinking water purifiers use a special technology called reverse osmosis (RO). RO was developed in the 1970s as a more economical replacement for distillation to desalinate sea water. In the home, a reverse osmosis drinking water filter will remove all contaminants from your tap water. It will even remove contaminants that carbon filters will not. The major problem preventing the widespread usage of reverse osmosis home water filter is the cost. Owning, maintaining and operating a home water filter of this type is beyond the means of many families. Partly due to the operational cost (an RO home water filter will only produce 5 to 15 gallons of purified water for every 100 gallons it filters while discarding the rest), you are more likely to find reverse osmosis whole house water filters. A larger unit like this is more capable of recycling the discarded water, resulting in less waste.
At this point of time, the most popular home water filters are the carbon type. Since they can be reasonably cheap, and because they are also able to remove sediment, the pure sediment water filters (like polyester and ceramic) have become rather uncommon. Some high-end carbon-type filters come together with ion exchange systems. These are a good alternative to reverses osmosis filtration.