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How to Remove Hard Water Stains From Granite

Scott Winfield
Written by Scott Winfield
Last Updated on

Granite countertops look quite cool, but once they start showing white and cloudy stains that resist all your attempts at clearing them, they lose their appeal very quickly. The culprit for these stains is hard water.

Hard water is water that contains an abundance of minerals, especially calcium and magnesium. Since these minerals have a tendency to build up and adhere to surfaces, they cause clogging in pipes and appliances and stains on kitchenware and countertops, including those made of granite.

Stained and Clean Granite Top
Stained and Clean Granite Top

Because granite is a natural and fragile stone, the most common solutions to hard water stains, like diluted white vinegar or rubbing alcohol, are not recommended. The high acidic content in vinegar and alcohol might cause abrasion on your granite countertop.

The good news is, you can easily remove hard water stains from granite by making a cleaning paste with baking soda. In this article, we’ll guide you through this process and provide solutions to prevent hard water stains from ever happening again.

Removing Hard Water Stains from Granite With Baking Soda

Cleaning Granite with Baking Soda
Cleaning Granite with Baking Soda

As we said, the commonly used acidic liquids, including white vinegar and rubbing alcohol, might damage granite since it’s a fragile stone. So, that leaves us with baking soda as our only recommendation for treating hard-water stains on granite.

That said, baking soda isn’t a fast solution. Here’s a rundown of the steps you need to take:

  1. Half-fill a cup with baking soda.
  2. Sprinkle 2 to 3 tablespoons of water on the soda. You can adjust the amount of water so that the mixture gets to a spreadable (paste-like) consistency. It’s best to use boiled, distilled, or bottled water since hard tap water is counter-productive when it comes to removing hard water stains.

Important: Some guides on the internet might suggest adding some hydrogen peroxide to the mixture. Don’t do it. Hydrogen peroxide is acidic and might damage granite.

  1. Thoroughly apply the paste over the hard water stains.
  2. Wrap the surface of your countertops that you’ve covered with the paste with a plastic bag so no air can get inside.
  3. Let the covered paste remain on the granite for at least a day (24 hours).
  4. After 24 hours, unwrap the plastic cover.
  5. Pick up a soft-bristled brush or a non-abrasive sponge (the yellow side of a soft sponge might do).
  6. Gently scrub and wipe off the paste.
  7. Rinse with boiled, distilled, or bottled water.
  8. If there are still some stubborn hard water stains, you might want to repeat the process. This time, though, let the mixture with the plastic bag sit for more than 24 hours.

How to Protect Granite from Hard Water Stains

Needless to say, if you have hard water stains on your granite countertops caused by hard tap water, chances are that the stains will come back after a while, no matter how rigorously you clean them.

But you need not worry, as most water treatment brands offer ample solutions to hard water problems.

These solutions are the following:

  • Traditional, salt-based water softening units
  • Salt-free water conditioning systems
  • Electromagnetic water descaling devices

Now, let’s see how these appliances work and which of them is the best fit for you.

Water Softening Units

Water Softener
Water Softener

Salt-based water softening units have long been what comes to most people’s minds first when water softeners were mentioned. Nowadays, salt-free conditioners and electromagnetic descalers are also sometimes referred to as ‘softeners,’ but technically speaking, the concept of ‘water softening’ still belongs to those traditional devices that work with salt and feature two tanks (one for resin and one for brine).

That’s because these devices are the only water-softening solution that actually removes the minerals, like calcium and magnesium, that give water its hardness. The process of mineral removal is known as ion exchange:

  1. Water enters the resin inside the resin tank that directly intervenes in the main incoming water pipe to your household.
  2. This resin has a negative (anionic) charge that draws positively charged (cationic) mineral molecules to itself and binds them. Calcium and magnesium are among those cationic molecules.
  3. Once every two weeks, a brine solution that’s automatically prepared in the brine tank of these devices navigates through both tanks, flushing the mineral buildup and introducing new negatively charged molecules (of sodium or potassium) to the resin. This operation takes place in preprogrammed regeneration cycles.
  4. Users need to renew the salt stock inside the brine tank once every two months (approximately) for the regen process to be effective. We also recommend sanitizing the unit whenever you add salt.

Although these devices are the most old-school water softening solution on the market, they have one major advantage over other devices when it comes to protecting your granite surfaces: since they actually remove minerals, they have the best scale reduction rate (a whopping 99%) in comparison to salt-free and electronic alternatives.

But, they might not be ideal for everyone:

  • The two-tank design makes them bulky, so if you’re already short on space, you might not be able to find a place for them in your home,
  • The installation process requires the services of a professional plumber and might take a whole day,
  • They’re expensive, especially when compared to saltless and electronic units, with a decent device costing about $1,500,
  • Water softener salt releases sodium to the environment, which is not really eco-friendly – it can be detrimental for your soil and plants,
  • You need to purchase new salt every once in a while, which makes them even less economical in the long term.

Yet, they’re still the most effective way to prevent hard water stains on surfaces, be it granite or not. So, if you have no budgetary or spatial concerns and you want to invest in the most effective solution, then we recommend the SpringWell SS1 Water Softener. It’s the best water-softening device you can currently find on the market.

Salt-Free Water Conditioners

Salt-Free Water Softener
Salt-Free Water Conditioners

As we implied above, ‘water softening’ refers to the act of removing minerals. Since salt-free units just chemically alter the structure of minerals inside the water, they are called ‘water conditioners.’

Here’s how they do it:

  1. The water enters the only tank of salt-free conditioners.
  2. A template inside the tank targets the surfaces of mineral molecules.
  3. As a result, the mineral molecules start crystallizing. This process is referred to as template-assisted crystallization (TAC).
  4. When their surfaces become crystal-like, they lose their clinging properties. In other words, they can’t bind together or stick to surfaces, including granite.

Despite the fact that they don’t actually remove minerals from water, TAC systems have their benefits – especially when you compare them to salt-based units:

  • They’re more affordable, as their price tag is often less than $1,000,
  • They’re salt-free, which makes them both more eco- and budget-friendly than salt-based water softeners,
  • The single-tank design means that they’re more compact,
  • Since they don’t remove minerals, there is no way for minerals to build up within the system, so they require little or no maintenance.

However, they have a few cons when you compare them to traditional devices:

  • Salt-based softeners can remove at least 99% of minerals from water, while that number is only 90% for salt-free conditioners. Although this rate is enough to prevent hard water stains, some people might still want to opt for something more effective.
  • Similar to their salt-based alternatives, saltless units also require professional help during installation.

All things considered, though, salt-free conditioners can help you protect your granite surfaces and objects with great efficiency. If you agree, the Aquasana Salt-Free Water Conditioner is our uncontested recommendation in this category.

Electromagnetic Water Descalers

Water Descalers
Electromagnetic Water Descalers

If actually removing minerals is the thing that qualifies something as a ‘water softening’ tool, electromagnetic water descaling devices are even less qualified than saltless units. In strictly scientific terms, they don’t even alter the chemical structure of mineral molecules – they only prevent them from bonding with each other.

Case in point, they don’t feature a tank, either. Just an electromagnetic power unit that needs to be plugged into an electrical source and two sets of magnetic bands that you need to wrap up around the water pipe are enough for these devices to work:

  1. The main body of the unit produces a magnetic field.
  2. The magnetic bands help this field extend its influence to the insides of the pipe that they’re wrapped around.
  3. As the water flows through the pipe, the electromagnetic field breaks the bonds between molecules.
  4. As a result, the mineral molecules can no longer cause buildup problems in pipes and stains on surfaces, including granite ones.

This method has several advantages over traditional softeners and saltless conditioners:

  • They’re a lot more affordable, with prices changing between $200 and $400. They don’t require much in terms of initial investment or operation costs,
  • They’re extremely compact, and since they’re mounted on a pipe or a wall near the pipe, they take very little space,
  • Since the incoming water doesn’t leave the pipe to enter a tank, magnetic descalers don’t affect the water flow and pressure of the water in your home,
  • Once they’re plugged in, they require no maintenance at all,
  • Anybody can install these devices without the help of a professional,
  • Like saltless water conditioners, they require no salt, so they’re quite eco-friendly.

Yet, they do have limitations:

  • Their scale reduction rate is even lower than saltless conditioners, with 50%, so if your water supply is especially hard, they’re not the best choice,
  • The electromagnetic field requires a period of adjustment to start working effectively (two to three months with most devices)

But if you’re living in an area where the water isn’t that hard, these devices can protect your granite surfaces from staining. If that sounds good to you, we recommend the Yarna Capacitive, which is the best product in its category.


Hard water can cause white and cloudy stains on granite surfaces due to its high mineral content. Granite is a fragile stone, so using tried-and-tested acidic solutions like white vinegar might lead to further problems, like abrasion.

The best alternative fix would be making a baking soda paste with a bit of water and applying it to the hard water stains on your granite surfaces. However, as you keep using water from your kitchen faucets, the hard water stains will likely come back.

Water softeners, conditioners, and descalers, on the other hand, offer a long-term solution to all your hard water problems. Depending on the water hardness in your area, you can pick the type of device you like and get rid of hard water stains once and for all.

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Scott Winfield
Scott Winfield
My name is Scott Winfield and researching and writing about water filters and other strategies to purify water has become my full time passion in recent years. I'm glad that you found our site and you can look forward to authoritative and well researched content here to help you get the best in water.
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