SusanB wrote us recently to ask a question that many people people have probably asked after reading some of the postings here on the Water Testing Blog, but never bothered to ask anyone at the Water Testing Blog

Your site and many others talk about ‘reverse osmosis‘ water treatment systems all the time but never really explain how they work. Are they just some sort of fancy carbon filter or something? I really want to know because I need to do something about my bad water and if they’re no different, except in price, than a simple carbon filter then I won’t waste my money on one. Can you explain the difference? IS there a difference? Thanks!

Actually, SusanB, we have posted information on Reverse Osmosis Water Filters in the past that addresses most of the questions you asked… 🙂

And now, after re-reading our own posts we have decided that we really ought to locate and re-post a more user-friendly definition and explanation of reverse osmosis water filtration.

There are a range of water filtration systems available to today’s consumer to meet the different challenges of raising water quality. Often, a simple activated carbon filter does the trick, but many people have more complicated water problems, and find that they need more complex water filtration systems because of this. A reverse osmosis water filtration system will, in many cases, solve these more advanced problems.

Reverse osmosis (RO) water filtration is a multi-step water filtering process which works slowly but is extremely effective. Reverse osmosis systems are generally used to treat cooking and drinking water supplies. It’s often used in industry but works very well in the home. Reverse osmosis uses the principles of osmosis (in which material passes slowly through a membrane and is concentrated and purified in the process) to produce very clean water.

The first step is that a simple sediment filter is installed and all water to be used passes through it; the filter catches large particles of materials such as rust or calcium carbonate (a compound which is not at all harmful but which isn’t desirable in your drinking and cooking water – it’s commonly used as an antacid). Sometimes a second filter of a similar design, but more fine, is used after the initial filtering. An activated carbon filter traps organic chemicals, and then the RO filter, which is a very fine membrane, is used. It may be helpful to think of all these filters as being similar to sieves with differently-sized holes. Basically, the process of reverse osmosis water filtration would be akin to draining cooked food through a series of increasingly-fine sieves, rather than just emptying the pot into a basic perforated colander. Reverse osmosis water filtration systems, being more complex and increasingly sensitive, can trap far more contaminants than just one simple carbon filter. Some RO systems will, even after the water has passed through the RO membrane, use yet another carbon filter or, alternatively, an ultra-violet lamp, to purify the water even further. The result of all of this filtering is extremely high quality water.

Reverse osmosis is not the most efficient of all water filtration systems, and some have expressed concern about the fact that it takes approximately four gallons of processed water to result in one gallon of clear water. However, its effectiveness makes it a preferred water filtration method for many. Some describe it as “ultrafiltration,” which gives a sense of how powerful RO is. RO results in very pure water. The Water Quality Association says that RO filter systems produce water purity levels as high as 95 percent, which is extraordinary.

The fact remains that reverse osmosis water purification systems remove an astounding range of contaminants from your water. Arsenic, barium, cadmium, chromium (hexavalent), chromium (trivalent), copper, lead, nitrate, nitrite, radium 226/228, selenium, iron and TDS are all removed from your water with an RO system.

A reverse osmosis water filtering system is obviously more complicated than a simple carbon-filter water pitcher, but the benefits of its complex design are also obvious. For those who are concerned not merely with the aesthetics of their water – taste – but have more concrete problems with water quality, an RO water filter may be the best solution to your problem. ( source )

Well, SusanB, and everyone else reading this, we hope the information above helped you to understand a little bit more about the ways in which reverse osmosis water filters operate and the benefits they offer. Below you will find links to three popular reverse osmosis water filters units available from WaterFilters.Net.

WaterFilters.Net: Pentek RO-3500
Pentek RO-3500
3-Stage RO System

WaterFilters.Net: PuROLine 5000 RO System
PuROLine 5000 RO System
5-Stage RO; 100 Gallons/Day

WaterFilters.Net: PuROTwist 4000 Gold Series
PuROTwist 4000 Gold Series
4-Stage RO; 50 Gallons/Day

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