That’s right, reverse osmosis water units are hard to beat when you have a problem like salt in your drinking water supply. But most of us don’t have that problem; we get our water from a municipal supplier or from a chlorinated well. And, for those people, I’ve got good news indeed. You will get a better result from selective filtration systems than you ever could with reverse osmosis. In today’s article we will examine both systems and how they differ. Then you can decide which one is best for your situation.

Reverse osmosis (RO) systems work by pushing water against a semi-permeable membrane with pores so small that only objects the size of a water molecule, or smaller, will pass through. As a matter of fact, the pores are so small they will even reject a large part of the water itself along with minerals and most contaminants. In most RO systems, the rejected water is simply wasted. Typically, this amounts to about two or three wasted gallons for every gallon filtered.

Hard water or water with excessive minerals is a problem in many water supplies and the fact that RO systems remove these minerals is another plus for these systems. However, it also has been found to cause another problem.

The fact is we need some minerals left in the water because our bodies need them. The second largest component in our body after water itself is calcium. If we constantly drink water with no minerals we are drinking water that is slightly acidic and it wants to return to its neutral state. One way for it to do that is to swipe some calcium from our cells, bones or teeth to produce calcium carbonate, a neutralizing compound.

Since cancer cells seem to prefer environments which are slightly acidic, some health professionals are now questioning the wisdom of drinking such water over a long period of time.

When it comes to synthetic organic chemicals (SOCs), they usually have a smaller molecular structure than water, and will pass right through the membrane. These are compounds like herbicides, pesticides, etc. In order to get the dirty SOCs out of the water, RO systems must be used in combination with a carbon filter.

RO systems requires adequate water pressure to force the water against the membrane and, for some users, this may call for the addition of an inline booster pump.

You also will need to have a storage tank with these systems. RO systems only filter about one gallon, or less, an hour. At this slow rate the systems need a way to store the water needed for bathing, doing dishes, or laundry, whatever. The solution is a diaphragmed storage tank in order to keep pressure on the line.

All in all, they are bulky units, what with the filter, a storage tank, and, maybe, an extra pump. All of this often means more expense, usually requires a plumber to install, and leads to extra maintenance cost somewhere down the line.

Anymore, I feel like using a RO system where you could have used selective filtration is like hunting flies with a cannon…they’re clunky, expensive and give a dangerous result.

Now, let’s look at an alternative to reverses osmosis, the selective (or multi-stage) filtration system.

These systems also use activated carbon to clean up any drugs or chemicals that might be in the water, but this carbon is first blended with a chemically charged resin and compressed into a solid block composed of tiny, submicron pores.

It’s interesting that scientists say a solid block of activated carbon, one foot square on each side, has an adsorption area of five square miles! No wonder is does so well with chemicals and it still has plenty of capacity in the tiny pores to clean up chlorine-resistant cysts, like Cryptosporidium and Guardia and any remaining debris.

And the chemically charged filter resin…what does that do?

When heavy metal compounds such as mercury or lead come in contact with this resin, their positively charged ions break their bond with water and snap onto the resin like little magnets. Because of the difference in their molecular structure, the lighter metals such as potassium and calcium don’t react and remain in the water.

You noticed these systems don’t have bulky storage tanks, they don’t need booster pumps or electricity and, if they are correctly installed, they produce good, healthy water (all trace minerals intact) virtually without maintenance.

Should you happen to be dealing with a severe water problem, is always wise to consult with a technical representative for any system you are planning to use. They know their business and can almost always suggest a solution. If you have salty water, you should be aware that selective filtration is not designed to remove salt.