How to Remove Tannins from Water

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If you drink water from a private well, there’s a high likelihood that your water contains tannins. Although low levels of tannins aren’t harmful to health, in some cases, they can pose a number of aesthetic problems. Water that contains tannins may have a musty odor and may taste bitter. It might also take on an unpleasant murky yellow, red or brown color.

💡 What Are Tannins?

Tannins are a type of organic material that is produced naturally by decaying vegetation and plant matter. They’re usually found in earth, leaves, and the bark of trees, and have a browny-yellow color. Drinking water tannins can stain, so if you’re washing your laundry and porcelain in tannins-laced water, your white items may actually end up looking yellow.

Tannins are also known as humic or fulvic acid. They’re most likely to be found in low-lying areas, as well as marshy ground and coastal locations, where they seep into surface water sources. This is how they easily end up in shallow wells.

❓ Are Tannins in Water Harmful?

There are no worrying health effects of tannins from water to be aware of. The biggest issue with this simple contaminant is that it’ll affect water’s taste, appearance and smell, which is caused by the small, organic humic acid substances that form in the water.

Nobody wants to wash in water that looks dirty, especially as it’s known to cause staining. Equally, drinking water that’s murky or tea-like, has a bad smell and a tangy taste probably isn’t your idea of fun, either. And with tannin molecules causing fouling and staining, the water-based units in your home are at risk of permanent damage.

It’s for these reasons that many people wish to remove tannins from water, not because they’re recommended or required to be removed due to being dangerous to drink.

removing tannins from well water

🤔 How Do Tannins Get Into Drinking Water?

If you’re a fan of the outdoors, chances are, you’ve come across a fair few rivers and lakes that are brownish-orange. You probably assumed that this was caused by dirt or pollutants, but, more commonly, it’s a result of tannins.

When surface water passes over decaying natural organic materials, such as leaves, soil and plant matter, it causes the water to take on a brownish-amber tea-like color. It’s the tiny particles from plants – which are harmless to human life – that sometimes cause water to take on this color.

In the same way, tannin compounds can easily enter into water that’s used in private wells. When it rains or snows, water from the surface of the ground seeps through peaty soil or fermenting, decaying vegetation. By the time it reaches your well’s aquifer, it will have taken on an amber tone because of its tannins content.

You’re particularly likely to have tannins in your well water if you live in a low-lying, marshy or swampy area, or you live near to the sea or another large source of water.

📑 Effects of Tannins in your Home

The good news is that tannins aren’t dangerous for health – but it’s a known fact that these substances can still be a nuisance when they’re in your home’s water supply. The tea-like color of tannins is particularly annoying – it can act as a dye, which can sometimes stain laundry and white dinnerware. Tannins have even been known to cause staining on porcelain fixtures, presenting a recurring cleaning problem.

Color aside, you definitely won’t want to cook with or drink tannins in your water, whether they’re natural and safe or not. That poses a problem with cost – you’ll be required to spend money on bottled water for yourself and your family, and trust me when I say that can really add up on a per-monthly basis.

Washing or bathing in water containing tannins isn’t unsafe, but it’s hard to enjoy a pleasant spa experience when your water smells or looks dirty. You’re perhaps also worried about the tannin odor lingering on your skin and clothes after washing.

tannins in water

🧪 How to Test for Tannins in Well Water

The most simple means of testing for tannins, before parting with your money on expensive equipment, is to fill a glass with water and let it sit for several hours (preferably overnight). Your water may be orange in color, but that’s not a definitive sign of tannins. Iron and manganese, for instance, can also give water an orange tone.

If your water does in fact contain tannins, the water in your glass will have the same color all the way through after leaving overnight. If iron or manganese is your problem, the discoloration will settle at the bottom of the glass.

Once you have a better idea of whether your water contains tannins, your next step is to see how concentrated your water is. There are plenty of state-certified laboratories that can perform common tests for tannins on your well water – you’ll just need to send in a sample of your water.

In the case of tannins being present in your water, it’s probable that additional common well water contaminants, such as iron, hardness minerals, and sulfates are also present. You can arrange for a laboratory to test for these three contaminants at the same time as testing for tannins. It’s required to test for iron, as if you check for tannins alone, iron can create a “false positive” for tannins. This means that laboratories must test to see how much iron is present in your water, then subtract this following amount from your water’s tannins level.

✅ How to Remove Tannins from Water

There are a number of methods and equipment that can be used to remove tannins from water. Some of the most popular choices are as follows:

Ion Exchange

Iron exchange is most commonly known as a softening water treatment option for removing hardness minerals, using salt, or sodium. But a cation/ion exchange absorption process can also be used in water softeners to treat and remove a high concentration of various other “difficult” contaminants, including drinking water tannins.

An ion exchange media is typically stored in a large tank. This type of system tends to be installed at your home’s point of entry, providing water treatment for your whole home.

In this type of ion exchange, an acrylic or styrene-based chloride resin is most effective. Tannins have a negative charge, which means they’re attracted to the ion exchange resin or media.

Once the ions are exchanged, the anion resin will regenerate via salt frequently, which helps to keep the resin bed clean and fresh. Typical anion exchange water treatment resins are made to undergo regeneration once every two days to prevent organic fouling of the softening resin. When the system is regenerated, it can begin the softening ion exchange process again.

An added bonus of an anion resin is that it isn’t only capable of tannin removal – it’s also relatively good at reducing sulfate in water. However, the anion exchange water treatment method may produce unwanted effects on water’s pH, and can also change the chloride levels in water, so keep an eye on this if your end goal is water that’s more alkaline than acid.

I Recommend: Springwell Tannin Softener System

SpringWell Tannin Softener System
  • Removes hardness and tannins
  • Up to 15 GPM flow rate
  • 30K or 45K grain capacity
  • High capacity resin ensures long contact time
  • Virtually maintenance free – just monitor salt level
  • Bluetooth control via Springwell app

Reverse Osmosis

Reverse osmosis products are an extremely popular water purification method that have been used for years to properly tackle pretty much every difficult-to-remove impurity out there.

Whole house reverse osmosis systems combine a number of water filters, including a pre sediment water filter and a carbon filter, with a highly effective RO membrane, ensuring that more than 99.9% of all inorganic and organic matter in water is removed.

In RO water filters, water flows at a high pressure through a pre-filter, a carbon filter cartridge, RO membranes, and last of all, a post-filter cartridge, before passing out of your faucet.

This filtration technology is typically installed at your main water line (either at your home’s point of entry or the water line beneath your kitchen sink). Because of the high pressure required for RO membranes, you’ll often benefit from immediate access to clean drinking water from the technology when you turn on the tap.

While reverse osmosis water filters are costlier than some other whole house water treatment solutions, they’re made for a top quality tannin removal, which usually makes them worth their money.

What makes a reverse osmosis water filter so effective is its ability to treat and trap even the tiniest contaminants – which most other water filters aren’t capable of removing. This is thanks to the tiny pores in the RO membrane, which are around 0.0001 microns in size.

As well as tannins, an RO treatment system removes bacteria, chemicals, and fluoride. The membrane also removes heavy metals like lead, and other contaminants that could turn water brown, such as iron.

Something to keep in mind with RO membranes, however, is that excessive levels of tannins in your water may result in tannin resin depositing in the water treatment system, which could lead to deterioration and irreversible damage to the systems, particularly the membrane filtration component.

This could change the effectiveness of the system for the worse and reduce its expected life-span.

We Recommend: US Water Systems Defender Whole House RO System

US Water Systems Defender Whole House RO System
  • Effectively removes tannins
  • Highly efficient 5:1 produced to wastewater ratio
  • 2,000 – 8,000 GPD production rate
  • Customizable system
  • Additionally removes up to 99.9% of total TDS
  • Highly effective treatment system


Finally, oxidation is an alternative to a water softener system or a reverse osmosis water filter. You can use a jar test to show the concentration and the retention time you’ll need with this method of removing tannins.

There are many different types of oxidants that can help reduce tannin levels and improve water quality, with chlorine being a common option. The problem with using chlorine, however, is that it may react with your water’s tannin compounds and produce a carcinogen called trihalomethane.

❔ Frequently Asked Questions

Will a Carbon Filter Remove Tannins?

Activated carbon water filters are another option for removing natural compounds such as tannins and improving overall water quality. This technology uses a filtration process known as adsorption, causing the water’s contaminants to stick to the surface of the filter media, while water particles can pass through. As with all water filters, they have a limited capacity, but most have a life of at least 6 months, with some systems lasting up to 2 years.

The only setback of these water treatment systems is that activated carbon filters aren’t as effective as other methods – they’re made to help with chlorine and lead removal – which is why it’s best to combine this type of filter with an RO membrane or oxidation systems. Considering these filters are usually included as one of the many different stages of RO filters, if you’re interested in an activated carbon filtration purchase, you may want to make an investment in an RO ultrafiltration system.

How Can I Avoid Tannins In My Water?

Types of tannin compounds occur naturally in most surface water supplies, which is why it’s generally a lot easier to remove them with water filter systems or ion exchange resins rather than trying to prevent them in the first place. Shallow wells are more likely to contain a high tannin content, however, so if you’re considering building a well for your home, make sure it’s deep enough to avoid surface water supplies if possible. It’s also important that your wells are well-built and don’t have any cracks or holes to make it easy for tannin particles to get inside.

Which Is The Best Treatment For Tannin Removal?

You’ll need to consider many factors when deciding on the types of filters and the best treatment for you, depending on what you’re looking for. Perhaps, if you’re looking for clear water that’s also free of impurities such as nitrates, pesticide and herbicide chemicals, and bacteria, a reverse osmosis water filter is the best, most thorough purification option for you. But RO ultrafiltration products are also the most expensive, so if your well only really has a tannin issue, or you just want to get rid of brown/yellow water, you might want to consider a water softener with an ion exchange resin or an oxidizing filtration unit. These products tend to be better for smaller budgets while still being considered highly effective at tannin removal.

I Have A New Well. Is It Important To Test For Tannins?

Yes – before deciding on which system to use to get your water treated, you should get it tested. Don’t just check for tannins, as wells commonly contain bacteria and sulfur, too, which give water an unpleasant aftertaste, may affect water flow, and may even make water unsafe to drink. If your water isn’t clear, it may contain iron. Once you know what you need to remove, it’ll be easier to buy the right systems for the job.

  • Jennifer Byrd
    Water Treatment Specialist

    For 20+ years, Jennifer has championed clean water. From navigating operations to leading sales, she's tackled diverse industry challenges. Now, at Redbird Water, she crafts personalized solutions for homes, businesses, and factories. A past Chamber President and industry advocate, Jennifer leverages her expertise in cutting-edge filtration and custom design to transform water concerns into crystal-clear solutions.

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