Is Bottled Water Hard or Soft?

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Wondering whether your favorite bottled drinking water is classed as hard or soft water?

In this guide, we’ve discussed everything you might want to know about the hardness of bottled water products.

πŸ“Œ Key Takeaways:

  • Bottled water is usually hard due to the presence of magnesium and calcium carbonate minerals.
  • Some bottled waters are obtained from naturally soft water sources, and some are treated with purification processes that soften the water.
  • You can check the bottle label or search online to find out whether your favorite water brand sells soft or hard water.

🚱 What Is Hard Water?

First, let’s quickly recap the definition of hard water.

Hard water is any water that has a high mineral content. Calcium and magnesium are the two key hard water minerals. These minerals are present naturally in the environment and enter water as it flows over mineral-rich rocks and soils.

🚰 What Is Soft Water?

Soft water is the opposite of hard water: it’s water with a low mineral content.

Soft water might contain only trace amounts of calcium and magnesium, or it might be mineral-free. Some water sources are naturally soft, but soft water is most commonly achieved with treatment in a water softening system or a purification process that filters and softens water (like distillation).

πŸ”Ž Is Bottled Water Hard?

Bottled water is usually hard because its concentration of calcium and magnesium hardness minerals is naturally high.

The majority of bottled water sources, including surface waters and groundwater (like aquifers and springs) are hard. These water sources accumulate hardness minerals as water flows through or over mineral-rich rocks and soils.

An estimated 85% of tap water supplies in the US are hard, so it’s hardly surprising that bottled drinking water is also primarily hard.

A few of the best brands of bottled water

πŸ“ How Hard Is Bottled Water?

There isn’t a specific water hardness that applies to all bottled water products. The hardness of the water depends on a few factors, including the water source and how (if at all) it has been treated. We’ve discussed this in more detail below.

The usual hardness range for untreated bottled water is 61 – 120 mg/L. Most bottled water products are moderately hard.

Some bottled waters may have higher hardness due to their naturally high mineral content.

πŸ“ˆ Is Bottled Water Hardness Important?

You might have heard that water hardness is bad without actually understanding why. The reality is that water hardness in bottled drinking water isn’t important because hardness minerals have no effect on human health and aren’t regulated by the Environmental Protection Agency (EPA).

In fact, calcium and magnesium minerals contribute to a crisp, refreshing alkaline taste, which is why so many people enjoy bottled mineral waters.

The reason why water hardness is a concern in your home’s water supply is due to the damage that hard minerals can cause to your plumbing and appliances.

Mineral stains accumulate on fixtures and water-using appliances, as well as in your home’s plumbing and pipes, restricting water flow and reducing their efficiency.

But when you’re drinking water from a bottle, you may as well enjoy these essential minerals since they’re having no effect on the water in your home.

πŸ“‹ Factors Affecting The Hardness Of Bottled Water

Here are the 2 main factors affecting the hardness of bottled water:

The Water Source

The water source is the main factor that determines whether bottled water is hard or soft water.

Most water sources are naturally hard, but this is determined by the local geology. Water passing through limestone or other mineral-rich formations tends to pick up more minerals, resulting in harder water.

In some instances, water may exist in an environment that gives it little or no access to hardness minerals. For instance, bottled glacier water tends to be soft water because glaciers are usually frozen precipitation, rather than water that has interacted with mineral-rich rocks.

Often (although not always), bottled drinking water that comes from groundwater sources, like well aquifers and spring water, are likely to have higher hardness than water that comes from a surface source.

Holding a bottle of Mountain Valley Spring Water

Water Treatment

The methods that are used to treat bottled water before bottling may also affect the hardness or softness of the water. This only applies to bottled waters that are treated – many are bottled at the source with no treatment whatsoever.

There are a few water treatment methods that may cause bottled water to become harder or softer:

Water Softening

Soft bottled water can be achieved by processing the water in a water softening system. This exchanges calcium and magnesium ions with positively-charged sodium ions, which can’t form mineral deposits.

Water Purification

This water treatment method is more likely to be used for bottled water because it removes harmful contaminants rather than just preventing mineral buildup (which is a bit pointless in bottled drinking water).

A water purification or filtration process, such as reverse osmosis and water distillation, removes up to 99.99% of all impurities. This purified water is free from virtually all contaminants, including dissolved minerals.

Many bottled water brands that obtain water from municipal supplies use purification processes to make their water more appealing than normal tap water. However, some of these brands may reverse the water softening effects of the purification process by reintroducing minerals (see below).


Mineralization is a treatment method that may be used to give bottled water a more alkaline pH or a “mineral water” status. It may also be used to reintroduce minerals that were lost by the use of certain water treatment systems, like reverse osmosis systems.

Adding minerals to water increases its hardness, pH, and alkalinity. So, bottled water with extra minerals is likely to have a higher hardness than bottled water without the enhanced mineral content.

Inspection of bottled water processing plant

πŸ€” How To Find Out Whether Bottled Water Is Hard Or Soft

You can find out whether you’re drinking hard or soft water from your favorite water brand by checking the bottle label or searching online.

Some bottled drinking water brands share their water’s mineral content on the label, including the water hardness. This is especially common among bottled mineral water products.

Otherwise, a search online should bring up this information on the manufacturer’s website. You can also check the FAQs and contact customer service if necessary.

πŸ’° Can You Buy Bottled Soft Water?

Yes, you can buy bottled soft water. If you simply prefer the taste of soft water, there are options for you to consider.

Our advice is to buy glacier water or any water that’s advertised to have a low mineral content. Avoid alkaline and mineral waters, which often have more minerals present than the average water source.

You could also buy bottled distilled water (check that it hasn’t been remineralized post-treatment), although you might find that this water tastes “flat” or “plain” due to its complete lack of dissolved solids.

Buying soft bottled water

πŸ“‘ Final Word

There are no health concerns associated with hard water, so it’s not super important whether or not your bottled drinking water is hard.

It’s more important to know the hardness of your tap water, since high mineral contents can damage your water pipes and appliances.

  • Laura Shallcross
    Senior Editor

    Laura is a passionate residential water treatment journalist who holds an undergraduate degree in Print Journalism and a master’s degree in Creative Writing. Over a span of 5 years she's written on a range of topics including water softening, well water treatment, and purification processes.

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