An alkaline water filter works by adding minerals, such as calcium carbonate, back into drinking water – often after reverse osmosis treatment. This process helps raise the pH of filtered water, balancing acidity and improving overall taste.
For many households, pH is an overlooked part of water quality. While reverse osmosis (RO) systems are highly effective at reducing a broad range of contaminants, they also reduce the natural minerals that act as a “buffer” for pH levels. Without these minerals, the purified water becomes highly sensitive to its environment; when it’s exposed to air, it naturally absorbs carbon dioxide ($CO_2$), which converts into weak carbonic acid. This is why RO water often tests slightly acidic.
Alkaline filters restore balance, offering a refreshing finish while still supporting the benefits of comprehensive RO filtration. Together, they provide cleaner, better-tasting water and more control over what comes out of your tap.
Reverse osmosis vs. alkaline water
What is alkaline water?
Alkaline water is water with a pH level higher than 7, making it less acidic. It often contains alkaline minerals such as calcium and magnesium, which can contribute to its higher pH.
What is reverse osmosis water?
Reverse osmosis (RO) water is produced by forcing tap water through a semipermeable membrane that removes many types of dissolved substances. This process targets contaminants like lead, arsenic and certain chemicals, providing a cleaner, more reliable source of drinking water.
Reverse osmosis and alkaline water serve different purposes but can work together. RO systems focus on reducing a wide range of contaminants, producing highly purified water that is clean and reliable. Alkaline water, on the other hand, is water that has had its pH raised, often by adding minerals like calcium and magnesium.
When combined, reverse osmosis with an alkaline filter provides the best of both: thorough contaminant reduction along with balanced, great-tasting water. Culligan systems with remineralization options are designed to deliver this combination, so you don’t have to choose between purity and pH balance.
How does water become alkaline or acidic?
Water naturally interacts with its environment on the way to your tap. As it travels through soil, rock and pipes, it can pick up dissolved minerals or other substances that shift its pH level. For example, water that absorbs more calcium and magnesium often becomes alkaline, while water that collects excess carbon dioxide can become acidic.
Some of these changes are outside your control, especially if you rely on municipal or well water. However, treatment options such as reverse osmosis systems with an alkaline filter allow you to adjust water’s pH at home. This ensures a more consistent, refreshing taste while also addressing other water quality concerns.
Do reverse osmosis water filters change alkaline levels?
In most cases, standard water filters don’t significantly impact pH. However, reverse osmosis systems can slightly lower pH levels by reducing dissolved minerals.
That’s where post-filtration cartridges come in. Culligan’s Mineral Boost Cartridge is designed to add back beneficial minerals like calcium carbonate to RO-filtered water. This helps balance the pH, raise alkalinity slightly and improve the overall taste.
Is alkaline water good for you?
Alkaline water is often sought out for its crisp taste and the balance it brings compared to more acidic water. Some people also explore it for potential wellness benefits, though research is still ongoing and results are not conclusive. Here’s what to know.
Possible benefits of alkaline water
Alkaline water is often believed to have a wide range of health benefits due to the presence of minerals like magnesium. These alleged benefits include:
- Digestive improvements
- Metabolic improvements
- Weight loss
- Immune support
- Superior hydration
- Cancer resistance
Unfortunately, there’s not a lot of research or data to support such claims. Scientists and health experts are still debating the effect alkaline water has on human health, but for now, it’s smart to do your own research and stay wary of any promises that seem too good to be true.
Possible drawbacks of alkaline water
For most people, typical variations in drinking water pH haven’t been shown to cause significant health effects. While extreme levels of alkalinity may cause dry skin or stomach upset and acidic water is sometimes suspected of causing acid reflux, there aren’t significant health risks associated with pH level variations for most people. However, for those with kidney disease, it’s especially important to check with a doctor before making choices regarding alkaline water.
Is alkaline water bad for your home?
There’s frequently a link between naturally alkaline water and hard water problems. That’s because the same minerals responsible for water hardness, including calcium and magnesium, can reduce water acidity. As a result, alkaline water may be associated with common hard water symptoms like limescale buildup, impacted water flow or reduced efficiency of water-using appliances. However, this correlation is often specific to naturally occurring alkalinity — so an alkaline water filter won’t cause water hardness.
In contrast, acidic water can interact more directly with the pH level of your home’s plumbing system. If your water is highly acidic, it could corrode certain copper pipes and cause further reactions, possibly resulting in copper contamination of your drinking water.
How an alkaline water filter works
Water isn’t always naturally alkaline, but even when it is, its pH can shift as it interacts with minerals, pipes and other environmental factors. If you want consistently alkaline drinking water, the most effective option is a home system designed for remineralization. Pitchers or bottled alkaline water may provide short-term results, but they’re less comprehensive and create unnecessary waste.
Most alkaline water systems start with reverse osmosis filtration. RO uses pressure and a semipermeable membrane to reduce a wide range of contaminants, from heavy metals to chlorine. After this process, water is typically neutral, with a pH close to seven. However, exposure to air can introduce carbon dioxide (CO₂), which can lower pH slightly toward the acidic range.
To address this, many systems include a mineral boost cartridge as the final stage of treatment. These cartridges add back small amounts of minerals like calcium carbonate, helping buffer the water against pH changes caused by dissolved carbon dioxide to balance pH and enhance taste. Unlike naturally alkaline water, which can have high mineral levels that contribute to hardness problems, this controlled remineralization won’t meaningfully contribute to water hardness or limescale issues.
It’s worth noting that results can vary depending on your source water. A professional water test can show your starting pH and help set realistic expectations for how an alkaline filter will perform in your home.
Schedule your free water test.
Do you need an alkaline water filter?
Clean water is essential, but choosing alkaline water is a matter of preference. Scientific research hasn’t proven clear health benefits, so the decision often comes down to taste and how you want your water to feel.
Here are a few factors to consider:
- Taste: If the pH of your tap water is always fluctuating, it’s difficult to rely on a consistently crisp taste. An alkaline water filter helps make pH levels more predictable, allowing you to achieve your desired taste and balance.
- Health: While the benefits aren’t confirmed, trying alkaline water is generally safe for most people. It may be worth exploring to see if you notice a difference.
- RO filters: If you already have a reverse osmosis system, adding an alkaline cartridge is simple. If not, installing RO first gives you broad contaminant reduction along with the option to raise pH.
- Water hardness: Natural alkalinity can come with water hardness issues. A water softener can help address these problems, which is why water softeners and alkaline water filters can and should be used together.
- Preference: In the end, the alkaline vs. neutral vs. acidic water debate is all about what you prefer. While you don’t “set” a pH dial, you can customize your experience by choosing different remineralization stages. For example, Culligan’s Mineral Boost Cartridge provides a slow, controlled release to ensure a consistent pH rise of 1-2 points, giving you a smooth, balanced taste without the chalky over-mineralization found in some other systems.
Take control of your water quality
Every glass of water in your home should meet your expectations for taste and quality. While pH can feel like an invisible factor, it’s something you can influence with the right treatment system.
The first step is understanding your baseline. A quick litmus test can give you a rough idea, but a professional water test provides accurate results and helps identify other potential issues. From there, you can choose solutions like reverse osmosis with an alkaline cartridge — or pair it with a water softener — to get water that’s clean, balanced and reliable.
Start taking control of your water quality today by scheduling your free water test.
*Contaminants may not be present in your water.
