Do Hard Water Filters Actually Work?

Do Hard Water Filters Actually Work?

Everyone wants purified and clean accessible water available, day or night, in their home. If you live in a hard water area, you may be tempted to try a filter to eradicate this problem. Hard water filters claim to soften the water and remove the buildup of limescale caused by minerals, such as magnesium and calcium. Yet, many people are still uncertain whether water filters really work.

Hard water filters do work. They are designed to remove minerals from hard water. The most commonly-used filters are reverse osmosis, carbon, and water softeners. Hard water filters absorb the minerals from hard water and replace them with sodium ions.

Soft water has many benefits; there is little to no limescale buildup, therefore improves the taste of your water. You’ll even notice the difference when you take a shower! You can soften hard water using a hard water filter, but how does it really work? Let’s find out!

Read my comprehensive article about what hard water is.

What Are Hard Water Filters?

Hard water filters work by removing the minerals that contribute towards hard water. Some of these minerals include magnesium and calcium.

You can think of this filter as a magnet that uses ion exchange to soften the water. The process of ion exchange involves removing high concentrations of these minerals. Hard water filters then replace these minerals with salt (sodium chloride).

In most cases, hard-water filters are often installed in the incoming pipe which is where you need to soften the water.

This treatment may sometimes be installed at the start of the system where the water supply enters the house. This is usually a better option when the water is very hard and can clog the water pipes.

The table below shows the water hardness and its change units.

  Water Hardness Change Units – mmol/l
1. Very Soft Up to 1.5
2. Soft Over 1.5 to 4.00
3. Average Hardness Over 4.00 to 8.00
4. Hard Over 8.00 to 12.00
5. Very Hard Over 12.00


How A Hard Water Filter Works

Here is an overview of how a hard water filter works:

  1. First, hard water enters the filter.
  2. The water moves over tiny sodium chloride beads in the filter’s resin bed. Like a magnet, these attract the minerals present in the hard water. Minerals stick to the resin bed.
  3. The ions of these minerals are now replaced with positively-charged sodium ions.
  4. Softened water leaves the filter with the hard water minerals removed and replaced with sodium ions.
  5. Now, you will only get soft water in your home. So, say goodbye to nasty rings, clogged pipes, and soap scum.

Over time, however, you will need to go through a regeneration process with your filter, due to the resin beads becoming too loaded with hard water minerals.

During this process, the resin tank is pumped with brine. Hard water minerals and brine flush through the tank, leaving your filter ready for softening water again.

Types Of Hard Water Filters

Many types of hard-water filters are available. The type of filter you need depends on your purpose.

Here are some commonly used hard water filters below:

1. Activated Carbon Hard Water Filter

An activated carbon hard water filter, or charcoal filter, works with activated carbon particles.

These particles clean water from loose minerals like chlorine. Every pound of carbon (around 0.45kg) has a 100-acre surface area and absorbs water impurities.

A carbon filter helps to clean water (for drinking) and make it odor-free. Yet, it cannot remove dissolved substances and minerals.

This type of filter is usually installed in the faucet. Once the water has been softened, it can then be used for washing, bathing, and drinking.

Over time, carbon filters become loaded with impurities. So, you must change them if you want to keep them working. How often you change your filter depends on the water condition and use.

2. Reverse Osmosis Hard-water Filter

Another type of hard-water filter is the reverse osmosis filter. This system uses a membrane that removes minute particles that even charcoal filters cannot remove.

Because of the high cost, people often connect these filters to one tap in the house.

Of all the water passing through this filter, only around 10% is cleaned. The rest is wastewater.

Regardless, people prefer this hard-water filter because it removes much smaller impurities than other filters. So, you get high-quality drinking water.

Occasionally, however, you will need to clean or replace the filter annually to keep it working.

3. Water Softener

A water softener is suitable for areas where the water is very hard. This filter makes use of zeolite beads with a negative magnetic charge.

Ions are replaced with positively-charged sodium ions. The hard water minerals are attracted to the zeolite.

Water softeners help to remove minerals, thereby minimizing scale buildup. They also protect the water pipes and ensure longevity.

Read my Ultimate Guide to Water Softeners: Everything You Need to Know.

Benefits Of Using Hard Water Filters

Hard water filters may be costly, but it is worth the expense when you consider the benefits. Some of these benefits include:

  • Improving heating systems and hot water efficiency.
  • Softening the water, making it better for your hair and skin.
  • Enhancing the lifespan and performance of appliances. These include dishwashers, washing machines, kettles, etc.
  • Removing minerals from hard water, reducing the scale build-up on fixtures, pipes, and appliances.
  • Assists in managing energy costs. As your appliances work more efficiently and need fewer repairs, this will save you a lot of extra repair costs.


What Filter Is Best for Treating Hard Water?

Multiple types of water filters are available for treating hard water, but ion exchange softeners are known to be the most effective.

Sodium chloride filers are the best among these as they add sodium (salt) to the water.

Do Common Water Filters Work for Hard Water?

In most cases, simple water filters won’t help in treating hard water. Instead, these filters remove contaminants and chemicals like chlorine, pesticides, herbicides, and biological organisms.

Final Thoughts

Hard water is a significant concern in many households worldwide. This type of water can damage pipelines as well as home appliances.

Thankfully, you have hard water filters to help you out. Filters are an effective solution to soften water. Have you ever used a hard-water filter to soften your water?

The Filter Guy

Scott Birch is a water filtration installer and designer. He has worked in the industry for many years and is very familiar with and knowledgeable about residential water treatment equipment. Scott enjoys helping people get the most out of their water filtration systems and ensuring that their homes are getting the best possible quality of water.

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