The Ultimate Guide to Reverse Osmosis: How It Works and What It Removes

The Ultimate Guide to Reverse Osmosis: How It Works and What It Removes

 

💧 The Ultimate Guide to Reverse Osmosis: How It Works and What It Removes

 

Ever looked at your glass of tap water and wondered what's really in it?

Here in the UK, especially in areas like London, we often deal with "hard water"—water that's high in minerals like calcium and magnesium. While it's considered safe, it's also what causes limescale in your kettle.

But what about the things you can't see? From the chlorine used to treat the water to tiny traces of lead from old pipes, microplastics, and even pharmaceuticals, our tap water is far from the pure, crisp spring water our bodies truly crave.

 

The "Forever Chemical" Problem

 

This isn't just a guess. It's a growing concern backed by major research.

Recent collaborations, including work by Greenpeace and Pesticide Action Network (PAN) Europe, have highlighted the widespread contamination of our water sources. A 2024 study by PAN Europe members found that 94% of tap water samples and 63% of bottled mineral water samples across 11 EU countries were contaminated with TFA (trifluoroacetic acid).

What is TFA? It's a highly mobile, persistent by-product of PFAS pesticides, also known as "forever chemicals."

This is a serious issue. These chemicals are called "forever" because they don't break down, and conventional water treatment methods struggle to remove them. PAN UK has confirmed this is a significant and growing problem in the UK as well.

So, if even our tap and bottled water can be contaminated, what's the solution?

If you've started researching water purification, you've almost certainly come across the term Reverse Osmosis (RO). It's often called the "gold standard" of water filtration. But what is it, how does it work, and is it the right choice for your home?

Let's break it down in a way that's easy to understand.

 

🤔 What is Reverse Osmosis, Anyway?

 

In simple terms, Reverse Osmosis is a water purification process that uses pressure to force water molecules through an extremely fine filter, leaving contaminants behind.

Think of it like a high-tech bouncer at an exclusive club. The bouncer (the RO membrane) has a very strict guest list. Only water molecules (H₂O) are allowed in. Everyone else—like Mr. Lead, Mrs. Chlorine, and the rowdy "Forever Chemical" family—gets left outside.

This process is so effective that it can remove up to 99.9% of all contaminants, turning your tap water into incredibly pure, clean water.

 

⚙️ How Does Reverse Osmosis Actually Work?

 

An RO system isn't just one filter; it's a multi-stage process. While systems vary, most follow these key steps:

 

Stage 1: Pre-Filtration

 

Before the water even gets to the main event, it passes through pre-filters. This is a crucial step to protect the delicate RO membrane. These pre-filters typically include:

  • A Sediment Filter: This catches the "big stuff"—dirt, rust, sand, and other particles. Think of it as wiping the mud off your shoes before walking into a clean house.

  • A Carbon Filter: This filter is a superstar at tackling chemicals. It absorbs chlorine and chloramines (the chemicals that make your tap water smell and taste like a swimming pool). This not only improves the taste but also prevents chlorine from damaging the RO membrane.

 

Stage 2: The Heart of the System (The RO Membrane)

 

This is where the magic happens. After pre-filtration, your household water pressure is used to push the water through the semi-permeable RO membrane.

This membrane is incredibly fine—we're talking 0.0001 microns. That's thousands of times smaller than a human hair!

Only pure water molecules can pass through these microscopic pores. Everything else is rejected and flushed away in a waste stream (often called "brine").

 

Stage 3: Post-Filtration (The Final Polish)

 

The water that makes it through the membrane is now incredibly pure and stored in a small tank. When you turn on your tap, this water passes through one last filter:

  • A Post-Carbon (or "Polishing") Filter: This filter cleans up any lingering tastes or odours that the water might have picked up from the storage tank, ensuring the water that hits your glass is as fresh and crisp as possible.

 

✅ What Does Reverse Osmosis Remove?

 

This is the most impressive part. Because the RO membrane is so fine, it removes a vast list of contaminants that other filters simply can't handle.

Here’s a look at the most common ones:

  • Heavy Metals: 95-99% of lead, mercury, arsenic, cadmium, and more.

  • Total Dissolved Solids (TDS): This is the measure of all dissolved substances in your water, including minerals. RO is the most effective way to reduce high TDS, which is the main cause of hard water and limescale.

  • Chemicals: Fluoride (90-97%), chlorine, chloramines, pesticides, and herbicides.

  • "Emerging" Contaminants: This is a big one. RO is highly effective at removing modern pollutants like microplastics, pharmaceuticals, and PFAS (the "forever chemicals" we mentioned earlier, which are so difficult to filter by other means).

  • Biological: Cysts, bacteria, and viruses (though most UK water is already treated for these, the membrane is a final, near-impenetrable barrier).

The result? Water that is exceptionally pure. In fact, it's just pure H₂O, which is exactly what your body needs for optimal hydration.

 

💡 The Big Question: Are There Any Downsides?

 

Honesty is a core value for us at Kapino Water, so let's be upfront. While RO is the most powerful filtration method, it has one well-known characteristic: it removes everything.

This includes the "bad stuff" we just listed, but it also removes beneficial minerals like calcium and magnesium. This can leave the water with a slightly acidic pH and a "flat" taste.

For decades, the solution was to buy a separate "remineralization" filter, adding minerals back in after the water was purified.

 

The Kapino Water Solution: RO, But Better

 

This is precisely why we chose Reverse Osmosis as the foundation for our KW-01 Hydrogen-Rich Water Purifier Dispenser.

We believe you should start with the purest water possible. You can't make great-quality water if you're just filtering out some of the contaminants. You must remove them all.

Then, we solve the mineral problem.

  1. Purify First: Our 3-stage system uses a powerful RO membrane to strip water down to its pure H₂O form.

  2. Remineralise Intelligently: The purified water then passes through our unique CF-Strontium Rich Carbon Filter. This filter not only polishes the taste but also adds back healthy minerals, including strontium, which is known to support bone health.

  3. Enhance for Health: Finally, the system infuses the pure, mineralised water with hydrogen, creating antioxidant-rich water that can help fight inflammation.

You get the unmatched purity of Reverse Osmosis plus the benefits of healthy minerals and molecular hydrogen, all in one.

 

 Is Reverse Osmosis Worth It in the UK?

 

Absolutely. Whether you're in London with its notoriously hard water or elsewhere in the UK, an RO system gives you complete control over your water quality.

  • No more limescale in your coffee machine or kettle.

  • No more buying bottled water (which is expensive, bad for the environment, and often contaminated with microplastics and forever chemicals).

  • No more worrying about hidden contaminants like lead, microplastics, or PFAS.

It’s the ultimate peace of mind in every glass and the perfect foundation for a healthier life—a mission that's very close to my heart, as you can read in my story.

Ready to experience the purest water you've ever tasted?

Explore the KW-01 Water Purifier Dispenser Here

 

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