Are Water Softeners Bad for Copper Pipes?

Updated: April 7, 2021 by Zac Harding

There are many reasons why someone may want to use a water softener. In fact, they are heartily recommended for use by some leading experts. However, have you ever thought about the effect a water softener may be having on your delicate copper pipes?

In this article, we will be analyzing whether water softeners are bad for copper pipes.

If you have copper pipes, or if you need to use a water softener and wondered about the effect it may have on your pipes, then this is the article for you.

What Does a Water Softener Do?

A water softener turns hard water into soft water. It does this by taking out the calcium and magnesium from the hard water and replacing them with sodium.

Calcium and magnesium are elements that can make water harder to work with hence the name ‘hard water’ in the sense that they interfere with soap, making it harder to later and cause corrosion in the inner workings of your water system.

There have also been concerns over the safety of hard water for cooking and drinking, leading many homes and businesses to do anything they can to get rid of hard water in favor of soft water.

How Water Softeners Work

So, we know what water softeners do, now we need to explain how exactly a water softener works.

This will allow us to properly assess the effect a water softener (and in turn, soft water) has on copper pipes.

As we mentioned in the previous section, the main thing a water softener can do for your water system is to remove calcium and magnesium ions and replace them with sodium ions.

This allows the water to still have mineral content, without compromising the effectiveness of the water when laundering, washing, cooking, and cleaning.

Your water softener unit is installed within your household plumbing system, specifically in the area where water enters your home. This is so that it can target the water at the source.

Within the unit, there is a well made of resin, covered in molecules that bind to any positive ions in the water.

Now, these molecules are interesting because not only do they attract the positive calcium and magnesium ions from the water, but they also release sodium ions into the water. In essence, the calcium and magnesium stay in the resin and the sodium moves into the water.

What this process does is allow the water to flow into your home free of calcium and magnesium ions, but full of sodium ions instead. Sodium is, of course, salt.

This salt softens the water and makes it more efficient at lathering and safer for use in cooking and cleaning.

Over time, the resin tank becomes full of these calcium and magnesium molecules, and the sodium molecules get fully dispersed into the water.

When this happens the unit self-cleans by rinsing the tank with a saltwater solution. Typically this happens at a time where the water will not be being used (i.e. in the night).

The sodium in the saltwater rinses out all of the calcium and magnesium ions, replenishing the sodium back into the tank ready for more water-softening.

This process happens every few days, and you may also need to load up the unit with a bag or block of sodium chloride (salt) every so often to ensure there is always enough saltwater for the rinse cycle.

Are Water Softeners Bad for Copper Pipes?

Now that you know exactly what a water softener does, and exactly how they work, it is finally time to assess the effect (if any) that a water softener has on copper pipes.

We want to begin by pointing out that the water softener itself lies within the water softener unit. By this, we mean that everything is contained in one unit and tank where the water is treated before it enters your household.

With this in mind, in theory, the water softener itself will not have an effect on your copper pipes. However, the freshly softened water might.

What we mean by this is that the water that has been softened has had its minerals stripped. The calcium and magnesium ions have been replaced by sodium ions, and this is not enough mineral content for the water. To make up for this, water will try and strip minerals from other means.

Enter copper pipes. Copper is a mineral that can be utilized by water… and utilize the water it does!

Are Water Softeners Bad For Copper Pipes?

Effect of Hard Water on Pipes

Before we tell you how the soft water utilizes the copper in your pipes, we first want to make a short reference to the effect hard water can have on your pipes. Hard water and the minerals it contains can cause a build-up in your pipes.

Calcium and magnesium can solidify, wreaking havoc on the pipes within your water system. Of course, this is just one of the many reasons why people use a water softening system. Now, in comparison, soft water does not build up. So, what effect does it have on copper?

Soft Water Draws Copper from Copper Pipes

OK, so soft water will not build up in your pipes, so there is no need to worry about that. However, as we have already mentioned, soft water does utilize copper in some way.

It does this by pulling copper elements from inside the copper pipes to add to the mineral content of the water.

Essentially, your water will be attracting copper ions into the water, and because there is no other system to filter them out, they remain in the water. In terms of safety, there is much debate over this.

A small amount of copper in water is not especially harmful, but it should be avoided in large amounts.

“What about the pipes?” we hear you ask. Well, the constant removal of copper elements from the copper pipes will obviously reduce the amount of copper in them. This can cause tiny pinhole leaks to form.

The cause of this is corrosion. This is where the copper is totally stripped from a small area, causing water to seep out through these very small holes.

Over time the pipe can corrode completely, and it will also reduce water pressure within the home, as well as affect the amount of water usage in your home or business.

Final Verdict 

In conclusion, we have found that water softeners themselves are not bad for copper pipes, but softened water could possibly have an effect on them.

Luckily, it is far more common to find these tiny pinhole leaks on systems where there is localized corrosion, and a fix for this is to ensure that you have a whole-home system for water softening. This will prevent pitted corrosion which is the most common cause of these leaks.

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