There are three main water filter systems to consider today, distillation, reverse osmosis and multi-stage or selective filtration. In this article you will see they differ in cost per gallon of water produced, effectiveness, required maintenance and filtering speed. You will find the information needed to make a wise choice for you from the options available.



In my opinion, you can pick any of the drinking water filters, outside of your own body, and it is a good one. But some are much better than others.

The highest selling systems are reverse osmosis (RO), so let's start with them.

The main filter in these systems is a semi-permeable membrane about the thickness of a piece of celophane. Water that has been prefiltered to remove most of the large particles is then forced, under pressure, against the membrane and only particles the size of a water molecule, or smaller can go thru. For most of us in the US there are far more efficient and better ways of doing what this stage does because:

1) RO filters won't remove chlorine, pesticides or many other toxic synthetic organic chemicals because their molecular size is smaller than water's, so reverse osmosis systems must be used in conjunction with carbon filters.

2) Even under the required pressure, two-thirds or more of the water molecules cannot be forced through the membrane and they go down the drain as wasted water.

3) The yield rate of these systems is around one gallon of filtered water per hour. So, if you want to take a shower, you will need to invest in a special storage tank to hold the water under pressure.

4) Lead is a problem in our water and this stage does remove it. However, it also takes out the beneficial minerals such as calcium and potassium that our bodies need. This produces slightly acidic water that some health professionals think is unhealthy to drink on a regular basis.

These systems will produce filtered water at a cost of 18 to 24 cents a gallon and maintenance is always one of the user's chief complaints.

Okay, let's take a look at a distillation system (D).

Distillation is similar to nature's recycling system. In nature the sun heats the water; it evaporates and rises to the upper atmosphere, condenses in the cooler air and falls as rain.

With D systems, water flows over a heated surface, turns into a vapor that is sent to a cooling chamber where it condenses back into a liquid. Inorganic compounds such as minerals like lead, magnesium, calcium, etc. are removed in this process.

This system is very effective against bacteria. Any bugs chlorine might have missed such as cysts like Cryptosporidium and Giardia (bad bugs), will be zapped by distillation.

And, yes, as mentioned, the D systems will get the lead out, but, just like the RO systems, they remove all the healthful trace minerals as well.

The wide range of synthetic organic chemicals, drugs, etc. also escape the filtering effects of D systems since they vaporize right along with the water they move past the distillation process. Because of this, just like the RO systems, these units must be used together with carbon filters.

Distillation like reverse osmosis is slow and incredibly wasteful, wasting up to 80 percent of the water used. Distillation produces water at a cost of 20 to 26 cents per gallon.

The last systems we will look at are called multi-stage or selective filtration systems.

Activated charcoal or carbon has long been viewed as the best technology for removing chemicals compounds such as chlorine, chlorine byproducts, herbicides, pesticides, drugs, etc., so, the earlier versions of these systems simply ran water through a cylinder filled with a granular form of activated charcoal.

But, these simple designs:

1) Did not force all of the water to pass through the charcoal. Some of it was allowed to sneak between the filter's wall and the filtering media and,

2) There was some concern that these filters were not capable of removing the tiny microbes such as Cryptosporidium and Giardia.

A new technology was developed which made the two complaints mute. This new technology kept the filtering power of activated charcoal but changed its form. First, they mixed the activated charcoal with a resin that had been chemically charged and compressed the mix into a solid block composed of submicron pores.

The problems were eliminated since the water could no longer bypass the filter and the cysts were removed by the filter's tiny pores.

And, of course, the activated charcoal removes the chemicals like drugs, VOCs, SOCs, etc.

That leaves the special resin you mentioned...what does it do?

That resin causes any heavy metal ions in the water from metals like lead or mercury to break their bonds with water and snap to this chemically charged surface like a magnet to a piece of metal. However, the lighter minerals, such as calcium and potassium do not join in on the ion exchange, so, bottom line, the good stuff stays in the drinking water.

When you compare selective filtration technology to that of RO or D systems you can see why it has become the industry leader. Not only are they the cheapest systems to own and operate, they also produce the healtiest and cleanest water.

They work simply (no pumps, storage tanks or electricity), efficiently, quickly and very economically, producing a gallon of filtered water for less than 10 cents with virtually no maintenance.

Whatever you do from this point on, please, use some type of filter for your water other than your body.