How a Reverse Osmosis Water Filter System Works: Unveiling the Nitty-Gritty Details

How a Reverse Osmosis Water Filter System Works: Unveiling the Nitty-Gritty Details

We have to admit, we're undeniably biased when it comes to the Reverse Osmosis (RO) system we're about to cover, and it's for good reason - it's one of the most effective RO designs available on the market. The combination of a sediment filter, carbon filter, RO membrane, and post-taste filter leaves your water perfectly clear, clean and pure. By the time it flows from your dedicated drinking water faucet, you're savoring the epitome of the healthiest water your money can buy.

Stage #1: Sediment Filtration

Your water’s journey begins with a sediment filter to trap larger particles such as loose dirt, rust, and other debris carried by stormwater runoff. It also removes the cloudiness and discoloration that can turn your water yellow, orange or brown.

Sediment filters uses a process known as mechanical filtration, a fancy term that basically means physically blocking out unwanted particles. Think of it as a legendary coffee filter or an armed bouncer guarding the club entrance. – allowing only the good stuff to pass through while keeping the unwanted debris out. Similarly, sediment filters enable water to flow through while effectively trapping the contaminants.

Nonetheless, sediment filters are not designed to capture total dissolved solids (TDS), heavy metals, chemicals, bacteria, or viruses;  that’s for the other filters to take care of later on.

The sediment pre-filter also serves a crucial role as a preliminary safeguard for the entire RO system. To be precise, it protects the flow restrictor, RO membrane, and carbon filter from clogging. While carbon filters can effectively remove certain sediment, larger particles of dirt can still quickly clog it.

Ultimately, the sediment filter plays a pivotal role in helping the carbon filter maintain water pressure and operate with maximum efficiency. Over time, this translates to an extended lifespan for the system and saves you money by minimizing the need for frequent replacements.

Relative size of Micron

Sediment filters are evaluated based on their capacity to remove particles of specific size, measured in microns which correspond to one-millionth of a meter. To put this into perspective,  the thickness of a human hair falls between 50-80 microns and anything smaller than 35 microns requires a microscope to be visible. For residential RO systems, the preferred choice is often a sediment filter with an estimated rating of 5 microns.

After the water passes through the sediment filter, it moves on to the carbon filter...

Stage #2: Carbon Filtration

Carbon block filters are essential in almost all types of water filtration systems. They specialize in capturing compounds that give unpleasant odors and tastes to your water, such as chlorine and volatile organic compounds (VOCs). Much like sediment filters, carbon filters protect the RO membrane from excessive wear and tear. The combined use of charcoal and sediment filters can extend the lifespan of your RO membrane by 1 to 2 years.

Not only are carbon block filters beneficial for your water quality, but they also contribute to a more eco-friendly approach by reducing the number of toxins in the RO membrane. While sediment filters rely on mechanical filtration to trap particles, carbon filters remove impurities through absorption.

You might have heard carbon block filters referred to as charcoal filters, but they don't contain the same type of charcoal you use for your barbecue. Instead, they are loaded with activated carbon, a specialized form of carbon created through the oxygenation of charcoal. This process creates millions of tiny pores that act as binding sites for contaminants to adhere to.

How does it work?

Step #1: The magic of activated charcoal comes into play as it transforms chlorine molecules into harmless chloride.

Step #2: The chloride ions cling to the filter's porous structure, allowing only clean water to pass through.

Some of the most common types of carbon filters are:

  • Carbon block 
  • Granular activated carbon
  • Coconut shell carbon
  • Radial flow carbon

Coconut shell carbon stands out as the eco-friendly among these options.
While a charcoal filter can do wonders for purifying your water on its own, achieving the purest water possible requires it to join forces with an RO membrane and a post-carbon filter...

Stage #3: Reverse Osmosis Membrane

Now it's time for the RO membrane to shine and work its purification magic!
With sediment, chlorine, and excess minerals already eliminated from the process, it's time to target the most nastiest and stubborn pollutants. Even though these impurities are so tiny to be seen even with an electron microscope, they’re still no match for reverse osmosis.

Unlike a simple carbon water filter, a reverse osmosis membrane can separate and dissolve inorganic contaminants, such as:

  • Lead
  • Arsenic
  • Radium
  • Chromium
  • Copper
  • Nickel
  • Fluoride
  • Bacteria
  • Herbicides
  • Pesticides
  • Pharmaceuticals
  • Nuclear particles
  • Uranium
  • Polyfluorinated substances (PFAs)
  • Volatile organic compounds (VOCs)

How does it work?

1. A flow restrictor applies pressure to force water through a compact, semi-permeable RO membrane.
2. Water naturally moves from the more concentrated side to the less concentrated side.
3. The contaminants are effectively trapped on the contaminated side.
4. The leftover water is then disposed of as drain water.

And now for the grand finale...

Stage #4: Post-Taste Filter

Lastly, the post-taste filter employs an additional cycle of carbon filtration to remove any remaining contaminants while enhancing the water's flavor.
A reverse osmosis filter system takes roughly one minute to filter 2 to 3 ounces of water, gradually storing it until you're ready to quench your thirst. When you turn on the tap to fill your glass, water flows from the storage tank and passes through the post filter before reaching your faucet.

This final touch ensures that your water is not only purified and free of contaminants but also provides a delicious, crisp taste that quenches your thirst perfectly.
So, as you enjoy a glass of water from your designer faucet, savor the knowledge that every stage of this RO system has played a crucial role in delivering drinking water at its purest, most pristine, and most delicious form.
Water you waiting for? Get yours today!

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