Will a 5-micron filter remove calcium?

💧 Struggling with limescale in your pipes? Frustrated that your 5-micron filter isn't solving the calcium problem? You're not alone. This guide cuts through the confusion-here's what you need to know.

If you're here, you've likely asked: "Does a 5-micron filter remove calcium?" Let's start with the answer you need:

🔍 Short answer: No. A 5-micron filter cannot remove calcium from water. Here's why:

How 5-Micron Filters Work

5-micron filters rely on physical filtration-they act like a mesh, trapping particles larger than 5 micrometers (μm). For context:
1 μm = 1,000 nanometers (nm).
Calcium and magnesium ions (the main minerals in hard water) are tiny, just 0.3–0.4 nm in diameter.

So it cannot be effectively removed by a standard sediment filter of micron grade.

In simple terms, A 5-micron filter is like a soccer net trying to catch grains of sand. It stops big "particles" (dirt, rust, even some bacteria) but lets dissolved calcium ions flow right through.

What is calcium?

Calcium is an essential mineral for the human body. It strengthens bones, helps muscles move better, and is particularly important for protecting bones. In daily life, we usually get calcium from milk, cheese, dairy products, and some vegetables. However, we don't want the calcium content in water to be too high. Why do we say that? Is calcium carbonate in water bad for you? Let's read on.

What are the harms of calcium in water?

As mentioned above, while calcium is an essential mineral, too much calcium in water can have several harmful effects. They include:

So, removing calcium is essential in water treatment. So we can't help but wonder: Can the filter cartridges in a home water filter remove calcium? If not, what filter cartridge do I need to remove calcium from my water? Before we figure out this problem, we must first understand what a micron filter is.

Key Differences

What They Share: A Critical Limitation

Neither 1-micron nor 5-micron filters can remove dissolved calcium (or magnesium, iron, etc.). They tackle particles, not dissolved minerals.

How small is a micron?

A micron, also known as a micrometer, is a unit of length equal to one-millionth of a meter. To provide a visual understanding of how small a micron is:

• 1 micron is approximately 0.000039 inches.
• A human hair is typically around 70 to 100 microns in diameter.
• A red blood cell is about 5 microns in diameter.
• A bacterium can range from about 1 to 10 microns in size.
• A particle of dust might be around 2 to 100 microns in size.

In summary, a micron is an incredibly small unit of measurement, often used to describe the size of particles, contaminants, or the filtration capabilities of filters and membranes due to its precision in measuring very fine dimensions.

Types of micron cartridge filter

When we talk about micron cartridge filters, we usually mean sediment filters, which are filters that can effectively remove dirt, sediment, and other particulate matter from water. There are many types of micron filters, and the four most common and commonly used ones on the market are Pleated filters, Melt-blown filters, String-wound filters, and Bag filters.
We list them in a table:

Picture
Type	Pleated filter	Melt-blown filter	String-wound filter	Bag filter
Advantages	Large Surface Area: The pleated design provides a large filtering surface area for increased filtration efficiency. Long Life: Pleated filters typically live longer due to the large surface area. High Efficiency Filtration: Capable of effectively capturing fine particles and particulate matter.	Economical price: PP melt-blown filter elements are usually economical and affordable. Wide applicability: Suitable for many different liquid filtration applications.	Lower cost: String-wound filter elements are usually more economical. Wide applicability: Suitable for filtering needs of different particle sizes and types.	High Capacity: Bag filters usually have a higher capacity and are suitable for filtering large flows. Easy to Replace: Replacing bag filters is usually simpler and faster.
Disadvantages	Higher cost: Pleated filters are generally more expensive than other types of micron filters. Difficult to replace: Due to the complexity of the design, replacing pleated filters may require more time and labor costs.	Lower filtration efficiency: PP melt-blown filters may have lower efficiency relative to other types of micron filters. Easy to clog: PP melt-blown filters may be prone to clogging when handling large amounts of particulate matter.	Limited filtration accuracy: The filtration accuracy of string-wound filters may be limited. Susceptible to damage: It may be susceptible to damage when handling larger particulate matter.	Higher cost: Bag filters can be more expensive relative to other types of micron filters. Large design: Bag filters can require more space due to their design.

 

What does a micron filter remove?

As we have mentioned in the previous section, micron filters are expressed in terms of filtration accuracy. Different filtration accuracies can filter different suspended solids and particulate matter to meet different water treatment requirements. The most common filter elements on the market are 100-micron, 50-micron, 10-micron, 5-micron, 1-micron, and 0.5-micron.

How many microns should my water filter be?

We have listed before what substances can be filtered by filters of different sizes. You can choose according to the situation. Generally speaking, the most commonly used sizes of household filters are 5-micron and 1-micron. This filtration accuracy can ensure the filtration effect and a certain amount of water output. It is most commonly used in primary filtration.

If 5-micron filters won't remove calcium, what will? Here's your roadmap:

Solution 1: Reverse Osmosis (RO) Systems

How it works: Uses a 0.0001-micron membrane to block 95–98% of calcium (and other ions like lead or fluoride).

Best for:

• Homes that need drinking water (e.g., Texas, where hard water is common).
• Labs, hospitals, or breweries require ultra-pure water.

Pros:

• Removes 95%+ calcium.
• Also filters heavy metals.

Cons:

• Wastes water (3:1 ratio of wastewater to clean water).
• Requires membrane replacement (~$100/year).

Solution 2: Water Softeners (Ion Exchange)

How it works: Swaps calcium/magnesium ions for sodium ions using resin beads. Removes 90–95% of calcium.
Best for:

• Homes that don't need drinking water (e.g., London, where tap water is often safe to drink).
• Large households (softeners handle high water flow).

Pros:

• No wastewater.
• Low maintenance (just add salt).

Cons:

• Adds sodium (avoid if you have high blood pressure).
• Needs salt refills (~$50/year).

Solution 3: Nanofiltration (NF) Systems

How it works: A 1–10 nm membrane removes 80–90% of calcium but keeps some minerals (like potassium).
Best for:

• Health-focused families (e.g., eco-conscious users in California).
• Those who want "balanced" water (not ultra-pure).

Pros:

• Retains some healthy minerals.
• Lower waste than RO.

Cons:

• Less common (harder to find in rural areas).

Can a 5-micron filter reduce limescale?

A: No. Limescale forms when dissolved calcium crystallizes (e.g., in hot water). A 5-micron filter only removes existing limescale particles, not the dissolved calcium that causes new buildup.

Will a water softener make my water "unhealthy"?

A: Most softeners leave 5–10% calcium in water. For healthy adults, this is safe. If you have high blood pressure, pair a softener with an RO system for drinking water.

I live in the countryside with well water. Do I need more than a 5-micron filter?

A: Well water often has high calcium (300+ mg/L). A 5-micron filter removes dirt but not calcium-add a softener or RO system to prevent limescale in your pipes.

Is RO water "too pure" to drink long-term?

A: The WHO confirms that drinking water is not the main source of minerals (you get calcium from milk, veggies, etc.). RO water is safe for daily use.

Step 1: Test your water

Use a TDS meter (available online) to check calcium levels:

• <150 mg/L: Mildly hard (5-micron filter + occasional softening).
• 150–300 mg/L: Moderately hard (consider a softener).
• 300 mg/L: Very hard (RO or NF recommended).

Step 2: Match your needs

• Need drinking water? Go with RO.
• Need to protect pipes? Choose a softener.
• Want balanced minerals? Try NF.

Step 3: Get Ink-Blue professional help

Contact us for exclusive personalized water treatment solutions.

💡 Final Takeaway: A 5-micron filter is great for cleaning particles, but calcium removal needs a smarter tool. Use this guide to pick the right solution-and say goodbye to limescale.

References

World Health Organization (WHO): "Guidelines for Drinking-Water Quality" (4th ed., 2017).

NSF International: "NSF/ANSI 42: Drinking Water Treatment Units – Aesthetic Effects" (2023).

U.S. Environmental Protection Agency (EPA): "Hard Water: Problems and Solutions" (2022).

Water Quality Association (WQA): "Residential Water Treatment Systems: A Consumer Guide" (2024).