Reverse Osmosis Filter

There are two common types of water filtration used in top rated home water filters. Carbon filters and reverse osmosis filters use different techniques to remove such contaminants as bacteria, sediments, chemicals, metals and odor.

Simply stated, carbon filters work by passing water through one or more filtering compounds, whereas, reverse osmosis passes water through layers of filtering screens to remove contamination and impurities, then uses water to wash the screens.

Here is how a carbon filter works:

Water is passed through either granular activated carbon (GAC) or a carbon block which removes sediments, micro-organisms and organic compounds.

Some filters will use a micron membrane to remove sand and silt as an initial filtration stage.

Depending on the size and quality of the unit, water may pass through up to 7 or even 8 levels of filtration with each level removing more and more contamination.

Some filtration companies are now using KDF which is a patented medium for fluid filtration to enhance the capabilities of a carbon filtration system.

Studies have determined that GAC and KDF used in combination within a filter unit have a greater capacity to remove contamination than carbon filtration alone.

Carbon filters need to be replaced regularly based on the manufacturers instructions.

Reverse Osmosis water filtration works like this:

Water is first passed through a pre-filter screen to remove sediments and larger particles from the water.

Next water is passed through an even smaller screen to remove very small particles (bacteria, heavy metals, etc).

The third step is passing the water through a carbon filter to complete the filtration process.

As contaminants build up on the filtration screens, the reverse osmosis system uses water to wash the screens - called backwashing. This process can create a lot of waste water; as much as double the amount of water that was purified.

So which type of water filter should you choose?

That depends on your budget and you water usage. Generally, for home use a carbon filtration system provides adequate water purification at a lower cost that reverse osmosis water filtration systems. Reverse osmosis water filters require more water flow for the backwash process - potentially increasing your water bill. You will also need abundant water pressure for a reverse osmosis water purification to work properly.

Generally, it's our thinking that the higher level of water purification provided by a reverse osmosis water filter may be worth the cost if you have a family member with a very severely compromised immune system and you have the water flow to sustain the system. Otherwise, the less expensive and less complicated carbon filtration system will provide the average household with plenty of safe, clean water.