Why Reverse Osmosis Water Filters Produce Unhealthy Water

Why Reverse Osmosis Water Filters Produce Unhealthy Water

By Tom Neuman

Nowadays more and more responsible households and families are asking water quality related questions, such as "What can we do against our contaminated city water? or "How do we effectively filter our incoming water?" The most common used filtration and water purification systems for efficient drinking water filtration today are Point-Of-Use Systems (mostly Reverse-Osmosis Systems), and Point-of-Entry Systems (Whole Home Systems).

Reverse Osmosis Systems lack Effective Contaminant Filtration

Reverse-Osmosis Systems are the least expensive types of residential water filtration systems. However, most water filtration experts say that these water filters are not the best choice for homes with substantial contamination issues. They mostly only affect color, taste and odors and lack the filtration of contaminants such as bacteria, molds, viruses, etc.

Frequent filter replacements, wasted kitchen space (gets in the way of using the sink and faucet for other purposes) and lack of long-term durability make them an unattractive choice compared to Whole-House-Systems, especially if someone is looking for a more permanent residential purification system that will be out of sight while doing its job.

How Reverse-Osmosis Works

In a Reverse Osmosis System (ROS) the water is passed through a 5 micron sediment filter to remove sediment, dirt and algae. In a next step, the water passes through one or two (depending on model) pre-carbon filters, which remove chlorine and other volatile organics from the water. In a next step the water reaches a reverse osmosis membrane, which removes minerals, leads, non-organic substances, chemicals, salt and more. The filter water then flows into a holding tank (4 gallon), which is an essential component to the system, since the process of reverse osmosis is not instantaneous.

The small pores of the ROS membranes are restrictive to such organic compounds as salt and other natural minerals. That means reverse osmosis is very effective at desalinating water and producing mineral-free water for use in print- or photo shops. In terms of removing dangerous chemicals and purifying drinking water, the reverse osmosis alone, without an additional carbon filter, is not sufficient, because the pores of the membrane block only large molecules like salt. Only Activated Carbon Filters are able remove the much smaller substances and chemicals like pesticides, herbicides and chlorine.

Major Disadvantages of Reverse-Osmosis Systems

¡Á Operates slower than an Activated Carbon or Sediment Water Filter

¡Á Some pesticides, solvents and other volatile organic chemicals (VOCs) are not completely removed by Reverse Osmosis because the pores of the membrane are blocking only larger molecules. A quality Granular Activated Carbon post filter is recommended; these filters are able remove the molecularly smaller substances and chemicals like pesticides, herbicides and chlorine

¡Á Reverse osmosis systems remove naturally occurring, healthy minerals and natural trace minerals will be blocked by the RO membrane. These minerals make the water tasty and serve as a vital function to our body system. Water without these trace minerals can actually be unhealthy for the body.

¡Á Damaged membranes are not easily detected. That means it is very hard to tell if the system is functioning normally and safely. If it's not, microscopic parasites can get through the membrane and contaminate the water

¡Á The waste of a large portion of water running through a Reverse Osmosis system is also problematic. The system generally wastes two to four gallons of water for every gallon of purified water it produces

¡Á Reverse Osmosis filter systems depend on a relatively high water pressure to force the water molecules through the membrane. In an emergency situation where water pressure has been lost, the system will not work

¡Á RO Water Filter systems require maintenance; the pre and post filters as well as the reverse osmosis membranes have to be changed according to the manufacturer's recommendation; the storage tank must be cleaned periodically