It depends, if you have brackish water laced with salt, then yes, one of the residential reverse osmosis systems is a good solution. But, if you are on a chlorinated water system, with no salt problems, there are simpler and far less expensive systems available. In this article we will look at why one of these systems, selective filtration, might be a better choice for you than reverse osmosis.

The increase of chemical toxins in our environment has led to a lot of discussion about our "body burden", the term for the total amount of these toxins in our bodies at any given time.

In the past, we worried a lot about the quality of the water we consumed and how it was affecting our bodies, and rightly so, but now scientists are discovering the quality of the air in our home poses an even greater load on our bodies. One of the largest offenders is chloroform, a byproduct of the chlorine in our water.

"Every home in America has an elevated level of chloroform gas due to the vaporization of chlorine...from the tap and shower water," according to the EPA. (It's true, the shower is the largest producer but the dishwasher and the washing machine aren't far behind).

By removing the chemical toxins at the point of entry into our homes, using whole house purification units, we significantly improve both the quality of the water and the quality of the air.

And, there is a compelling reason to look at RO and SF technologies before you buy, because they differ significantly in initial costs and the cost to operate.

In today's world, cost differences might determine whether or not we can even buy a whole house unit. Very good residential selective filtration systems will run about $800. Comparable residential reverse osmosis systems are in the $10,000 range.

How do you explain the price differences?

One of the hardest things to remove from water is salt and, years ago, RO was developed as a cheaper way to clean up salt water than by using distillation. But that was when water and electricity were both very cheap. Today RO is an expensive technology as you will see.

RO systems use the home's water pressure to force water through a membrane having pores so small only molecules the size of water molecules, or smaller, can pass through, leaving contaminants with larger molecules behind.

Not all contaminants are stopped by the membrane. Chlorine, its byproducts and many other chemical compounds have small molecules that allow them to pass through easily. Carbon filters are added to remove them and to protect the membrane.

Smaller RO systems are very slow producers and typically take two to three hours to deliver one gallon of water. Whole house units are much faster, producing in the area of 1,800 gallons per day. Both large and small units require pressurized storage tanks to provide any quantity of filtered water.

The smaller RO units need the home's water pressure to be at least 40 psi (pounds per square inch) to operate efficiently. Older homes, or well water systems, may require booster pumps. Whole house systems typically come with booster pumps.

A lot of water is wasted, even with adequate pressure in the system, because for every gallon filtered, often 2 to 5 gallons of water cannot be pushed through the membrane. This water is then flushed, along with the filtered contaminants.

There are some systems that do recycle this water but, recycling, electricity requirements, storage tanks and, possibly, extra pumps are what cause the high initial costs and some of the higher operating costs. Then too, the more things in a system that can go wrong, the more chances there are for additional maintenance issues to further increase the operating costs.

A good option to reverse osmosis, especially if you are on a chlorinated water system (which most of us are), is selective filtration.

In these systems, redox (reduction/oxidation), mechanical filtration and activated charcoal are integrated into a multistage filtering process that will quickly process the water at the whole house level.

The relatively new redox filter uses a chemical exchange process to remove toxic metals, such as dissolved mercury or lead, from water. RO and distillation can also remove lead, but redox filters uses the first technology capable to remove these toxic metals by simple filtration methods.

Chlorine and its byproducts, along with other organic chemicals, are 99 percent (plus) removed by the activated charcoal. And, the total process treats water somewhat like a water softener, with no sodium added, and the odors, bad tastes and sediment are also removed.

These systems produce filtered water rapidly (over seven gallons per minute), without electricity, storage tanks, or booster pumps. Their simplicity also makes for simpler installations.

For anyone wanting to improve the air and water quality in their home, selective filtration systems are a viable cost saving option to consider.