a photo of a pH paper testing water acidity

Water is essential for health and everyday use, and its quality is critical. Reverse Osmosis (RO) systems purify water by removing contaminants, but they can also lower its pH, making it slightly acidic. Alkaline filters correct this, maintaining a neutral pH balance in water, which is beneficial for health. Let's discuss the importance of water pH and how RO systems combined with alkaline filters improve water quality and health.

Basics of Reverse Osmosis (RO) Systems

For many, the term "Reverse Osmosis" might sound like something straight out of a sci-fi movie. However, it's a widely adopted and scientifically proven method for purifying water. 

What is Reverse Osmosis?

At its core, Reverse Osmosis is a water purification process that employs a partially permeable membrane to remove unwanted particles, molecules, and larger ions from drinking water. This technique harnesses water pressure to push tap water through this specialized membrane, allowing only purified water to pass through, while the contaminants are flushed away.

Main Components of an RO System:

  1. Pre-filters: Before water encounters the RO membrane, it goes through pre-filters. These pre-filters remove larger contaminants like sediment and chlorine, which can clog and damage the delicate RO membrane.

  2. RO Membrane: This is the heart of the system. It's a thin film made of specialized material that effectively traps contaminants while allowing only clean water molecules to pass through.

  3. Post-filters: After the RO process, water might still have some lingering taste or odor. The post-filters address this by further polishing the water, ensuring it’s fresh and clean for consumption.

  4. Storage Tank: Once purified, the water is stored in a tank, ready to be dispensed when you turn on your tap.

  5. Drain Line: This is an outlet for the impurities and contaminants removed from the water during the RO process.

Benefits of Purified Water from RO Systems:

  1. Contaminant-Free: An RO system efficiently removes up to 99% of dissolved solids, chlorine, fluoride, and other harmful substances, ensuring that you get the purest form of water possible.

  2. Improved Taste and Odor: By eliminating impurities, RO systems deliver water that's not only healthier but also tastes and smells better.

  3. Economical and Environmentally Friendly: Instead of buying bottled water, which can be both costly and detrimental to the environment due to plastic waste, an RO system offers a sustainable and cost-effective solution for clean drinking water at home.

For clean water, an RO system stands out as an exemplary method of purification. However, the process of removing contaminants sometimes strips the water of beneficial minerals, which can lead to a shift in pH levels. As we proceed, we'll explore the significance of pH and how alkaline filters can play a pivotal role in restoring this balance.

The Science of Water pH

Water pH isn’t just a concept reserved for scientists in their labs; it's an essential metric for assessing the quality and safety of our drinking water. 

pH stands for "potential of hydrogen." It's a logarithmic scale used to specify the acidity or alkalinity of an aqueous solution. The scale ranges from 0 to 14, where 7 is neutral. Anything below 7 is considered acidic, and anything above is alkaline.

Why is Balanced pH Important for Drinking Water?

  1. Taste: Water with a balanced pH generally tastes better. Highly acidic or alkaline water can have a distinct and sometimes off-putting taste.

  2. Equipment Longevity: Acidic water can be corrosive. Over time, it can damage pipes, fixtures, and even appliances.

  3. Health Implications: While our bodies have a natural buffering system to handle variations in pH, consistently drinking water that's too acidic or too alkaline may have health implications. For example, very acidic water can leach metals from pipes, introducing them into our drinking water.

RO and pH Balance:

An interesting aspect of the RO process is that while it's superb at removing contaminants, it can sometimes produce water that is slightly more acidic. This is because many of the minerals that help buffer and balance water’s natural pH get removed in the purification process.

Potential Health Implications of Imbalanced pH:

  1. Acidic Water: While moderate consumption of slightly acidic water isn't typically harmful, long-term intake can potentially affect our body’s acid-base balance. Moreover, as mentioned earlier, very acidic water can lead to leaching of metals like copper and lead from pipes.

  2. Alkaline Water: Some studies suggest that alkaline water might help neutralize acid in the body and boost metabolism, but the evidence is still inconclusive. It's essential to ensure that the rise in pH isn't too high, as excessively alkaline water can taste bitter and affect your digestive system.

a photo of pH scale

While RO systems do a stellar job of filtering out contaminants, the resulting shift in pH cannot be ignored. This brings us to the crucial role of alkaline filters in rectifying this imbalance and enhancing the quality of our drinking water.

By understanding the importance of pH in our drinking water, we can better appreciate the benefits that alkaline filters bring to the table. 

The Role of Alkaline Filters in RO Systems

Having a comprehensive understanding of RO systems and the significance of pH balance, we now venture into the functions of alkaline filters. These filters are not just auxiliary components; they’re vital instruments that enhance both the quality and taste of RO-purified water.

Why RO Water Might Be Slightly Acidic:

When water undergoes the rigorous purification process of an RO system, beneficial minerals such as calcium, magnesium, and potassium, which naturally balance water's pH, are often reduced or removed. This demineralization can lead the water to lean towards the acidic side of the pH scale, especially when starting with source water that's already slightly acidic.

An alkaline filter's primary purpose is to reintroduce these essential minerals back into the purified water and, in doing so, raise its pH to a more alkaline or neutral level.

How Do Alkaline Filters Work?

  1. Remineralization: Alkaline filters often contain mineral beads or stones, such as tourmaline, maifan, or calcium carbonate. As water flows through the filter, it absorbs these minerals, increasing its mineral content and consequently its pH.

  2. Ionization: Some advanced alkaline filters use a process called ionization, where an electrical charge is applied to separate the water into its acidic and alkaline components. The alkaline water is then channeled for consumption, while the acidic portion is discarded or utilized for other purposes.

Benefits of Incorporating an Alkaline Filter with RO Systems:

  1. Mineral Enrichment: Beyond balancing pH, the reintroduced minerals enhance the nutritional value of the water. Minerals like calcium and magnesium are vital for bone health, muscle function, and overall well-being.

  2. Improved Taste: For many, water with a balanced pH and a slight mineral content tastes fresher and crisper than its demineralized counterpart.

  3. Optimal Hydration: With a balanced pH and essential minerals, water is believed to hydrate more effectively, aiding in cellular function and overall bodily processes.

  4. Potential Health Benefits: Though research is ongoing, some believe that consuming alkaline water may offer benefits such as neutralizing excess acidity in the body and improving metabolism.

While RO systems are powerful tools in the purification arsenal, the inclusion of an alkaline filter elevates the water's quality to the next level. It's a synergistic relationship where each component complements the other, ensuring that every drop of water you consume is both pure and optimally balanced.

How Alkaline Filters Affect Water pH

Having established the integral role of alkaline filters in RO systems, it’s time to discuss the tangible effects these filters have on water pH. It’s this transformative process that ensures the water you drink not only tastes great but also meets optimal health standards.

The Process of Remineralization:

One might wonder, if RO systems are so efficient at removing contaminants, how do we selectively reintroduce only beneficial minerals? The answer lies in the sophisticated design of alkaline filters.

  1. Addition of Essential Minerals: Most alkaline filters come packed with mineral beds containing elements like calcium, magnesium, and potassium. As the RO-purified water flows through these beds, it naturally absorbs these minerals, leading to both an enhancement in taste and an upward shift in pH.

  2. Controlled Release: These filters are designed to release minerals in controlled amounts. This ensures that the water doesn’t swing too far towards the alkaline side and remains in the optimal pH range for drinking water, typically between 7.0 and 9.5.

For example, the NU Aqua Platinum Series 6 Stage Alkaline 100GPD RO System enriches water with minerals such as:

a photo of the NU Aqua Platinum Series 6 Stage Alkaline 100GPD RO System
  • Calcium: Vital for strong bones and teeth, and important in maintaining blood pressure and heart health.
  • Magnesium: Crucial for bone health, blood sugar regulation, and nerve function.
  • Selenium: An antioxidant important for cell protection and thyroid function.
  • Zinc: Involved in wound healing, immune response, and taste sensitivity.
  • Iron: Essential for producing red blood cells and distributing oxygen throughout the body.

This kit also includes Maifan, Tourmaline, and ORP Balls, which are believed to offer extra health advantages like enhanced energy, better sleep, and reduced inflammation.

The concentration of minerals reintroduced to the water depends on its original mineral content. If your water already contains a high mineral level, the difference after filtration might be minimal. However, water with initially low mineral content could taste better and be more hydrating post-filtration.

In summary, the NU Aqua Platinum Series 6 Stage Alkaline 100GPD RO System is beneficial for those looking to replenish minerals in their water after processing it through a reverse osmosis system.

From Acidic RO Water to Neutral or Slightly Alkaline:

The beauty of integrating an alkaline filter with an RO system is the harmonious balance achieved. While the RO membrane strips the water of contaminants and some essential minerals, the alkaline filter steps in to restore the necessary mineral balance and, in doing so, neutralizes the acidity.

  1. Balanced Hydration: With the pH adjusted to a more neutral or slightly alkaline state, the water becomes more biocompatible with the body, ensuring efficient hydration and absorption.

  2. Safety Measures: It's worth noting that a good alkaline filter will have safety mechanisms to prevent over-alkalization. This ensures that the water remains within safe and palatable pH levels, devoid of any bitterness or unnatural taste.

Ensuring Water Quality and Taste:

While the core focus of alkaline filters is pH adjustment and remineralization, they also contribute to the overall sensory experience of drinking water.

  1. Taste Profile: Water that is slightly alkaline with a balanced mineral content often tastes smoother and silkier, with many describing it as "sweet" or "fresh."

  2. Odor Improvement: By balancing pH and adding minerals, any residual odors often associated with demineralized or slightly acidic water are effectively neutralized, giving you a more pleasant drinking experience.

As such, while the RO system plays the pivotal role of purification, it's the alkaline filter that perfects the process. Together, they ensure that every sip you take is not only pure but also harmoniously balanced in pH, brimming with essential minerals, and a joy to taste.

Maintaining and Ensuring Longevity of RO Systems with Alkaline Filters

Investing in an RO system with an alkaline filter is a commitment to superior water quality. Like all sophisticated systems, they need regular maintenance to function optimally. 

1. Routine Checkups:

  • Frequency: At a minimum, inspect the system every six months. However, if your water source is known to be of lower quality, quarterly checks might be more appropriate.

  • What to Look For: Keep an eye out for decreased water flow, changes in taste or odor, or any visible damage or discoloration to the filter/system.

2. Filter Replacements:

  • RO Membrane: Typically, the RO membrane needs replacing every 12 months, but this can vary based on water usage and source water quality.

  • Alkaline Filter: Most alkaline filters last 12 months, depending on usage and the specific model. Ensure you're using the recommended replacement from the manufacturer or a trusted compatible filter.

  • Pre and Post-filters: The sediment and carbon filters (pre-filters) that protect the RO membrane from sediments and chlorine as well as the post filters should be replaced every 6 months. 

3. Cleaning and Sanitizing:

  • Frequency: It's advisable to sanitize the system annually. This ensures that any microbial buildup is kept in check.

  • Procedure: Follow the manufacturer's guidelines for sanitation. Often, this involves circulating a sanitizing solution through the system and then thoroughly flushing it out.

4. Monitor Water Quality:

  • pH Testing: Regularly test the pH of your output water to ensure the alkaline filter is functioning correctly. Simple pH test strips are available and easy to use.

  • TDS Meter: A Total Dissolved Solids (TDS) meter can give insights into the effectiveness of your RO membrane. If TDS levels start rising, it might be an indication that the membrane needs replacement.

5. Be Mindful of Water Pressure:

  • Optimal Pressure: RO systems work best under a specific water pressure range, usually around 60-80 psi. If the water pressure is too low, it can reduce the efficiency of the system and the lifespan of the membrane.

  • Pressure Gauge: Installing a simple pressure gauge can help monitor and ensure you're within the optimal range. If necessary, consider adding a booster pump.

Regular maintenance doesn't just prolong the life of your RO system with an alkaline filter; it ensures that the quality of the water remains consistently high. Remember, the key to longevity is a blend of routine checks, timely replacements, and a vigilant approach to any changes in performance.


Water is life's most essential element, and ensuring its purity is our foremost responsibility. By choosing an integrated RO and alkaline filter system, we're not just making a choice for superior quality water, but also casting a vote for a healthier lifestyle and a greener planet.

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