All You Need to Know About Reverse Osmosis Water Filters

Mar 29 , 2018

All You Need to Know About Reverse Osmosis Water Filters

Not all water that comes out of the faucet is pure and suitable for drinking. Without proper filtration, water could contain particles of dirt, bacteria, and viruses. Unfiltered water could also contain excessive quantities of minerals, such as calcium, that could build up in your home appliances and cause limescale. Installing a reverse osmosis water filter is an ideal way to ensure the cleanliness of your water. 

What Is Osmosis?

Osmosis is the flow of a less-concentrated solution to a higher-concentrated solution (lower to higher) through a semi-permeable membrane that does not allow larger particles to pass through it (see figure 1).


Conversely, reverse osmosis (RO) uses pressure to change the direction of water flow through the semi-permeable membrane. Instead, it flows from a concentrated environment to a less concentrated (higher to lower) environment (see figure 2). This process means that particles such as salt and fluorides can be removed from water using household pressure. The contaminants will be filtered out of the water, leaving you with clean, safe drinking water.


Why Do I Need a Reverse Osmosis Filter in My Home?

There are many benefits of installing a reverse osmosis filter in your home. Unfiltered water is unsuitable for human consumption. When water moves from the water treatment plant to your home, it passes through tens or sometimes hundreds of kilometers of piping before it arrives at your home. Along the way, it may pick up dirt and sand in addition to micro-organisms.

Many activities in and around the area can lead to contamination in the groundwater. Mining, for example, can leave many harmful chemicals in the groundwater, including arsenic and radium, which can be removed using a reverse osmosis filter. All these chemicals, if left untreated, can cause serious health effects to humans, as well as any produce that is grown with the help of well water.

What Are Some of the Main Components of the Reverse Osmosis Filter?

1.      Water valve: This is attached to the cold-water source and is the main, pre-filtered water supply for the RO system.

2.      First filter/pre-filter: When water flows through the water valve, it first encounters a pre-filter that protects the RO membrane from larger sediments like dirt.

3.      RO membrane: The RO membrane is the core of this filtration system. Here, the semi-permeable membrane physically removes the vast array of water contaminants. These membranes are typically made up of a thin, synthetic polymer layer that is topped by a thicker polyester barrier layer. Finally, a polysulfone layer is added to the polyester layer for swift transportation of the water. Additionally, the water flow is regulated by a restrictor.

4.      After filter: Once the water has been filtered through the RO membrane, it is filtered again, typically with a carbon filter, before reaching the faucet. This almost acts like a quality control to the RO membrane. It will be filtered into the storage tank.

5.      Shut off valve: When the storage tank is full, the RO system will automatically shut down in order to conserve water.

Reverse Osmosis Filtration: RO Systems

The Everpure EV9273-75 - ROM II Reverse Osmosis System and the Whirlpool WHER25 Reverse Osmosis Water Filtration System (figure 3) are two complete filtration systems suitable for the home or office. These systems can reduce contaminants like lead, nitrates, and dissolved solids that can damage home appliances and make water unsuitable for consumption.

Reverse Osmosis Filtration: RO Membranes

Conveniently, if you have an RO system and you just need a membrane, then you can also purchase a membrane. The membrane is the heart of the system and, so, it’s important to ensure that you choose a quality membrane to provide you with clean drinking water.

For example, you could choose The Ametek ROM-16C Reverse Osmosis Membrane—a durable membrane for commercial purposes; or the CSM RE2521-BLN 300 GPD TW-LE Commercial Membrane, known for its long filter life.

Reverse Osmosis Filtration: RO Tanks

The filtered water is stored in an RO tank. Depending on your needs, you can purchase a 14-gallon tank (RO-1070-W-14 14 Gallon NSF Tank-White-1/4 Metal Reverse Osmosis Tank) or a 28-gallon tank (TKE-2800W PAE RO-2800 28 Gallon White Metal Reverse Osmosis Tank).

Figure 3. The Whirlpool WHER25 Reverse Osmosis Water Filtration System

Is a Reverse Osmosis Filter Easy to Install?

The installation process is easy and uncomplicated. The components are compact and easily transportable. They can conveniently fit under the average household sink, and they only require a few simple household tools for installation.