WATER QUALITYWhat Does Tannins in Water Mean?

March 17, 2022

Maybe you’ve heard of tannins when it comes to wine. Maybe not. Probably not. Tannin is organic matter, actually decayed organic matter, and it’s in wine and gives the drink its dry feeling. You might be a connoisseur of fine wine, but you don’t want tannin giving weird smells, colors and taste to your water at home.

A high level of tannin is considered contamination in water. Tannin will give a yellow or brown color to water, similar stains to fixtures and a musty or bitter smell and taste to water. How can you know about tannin in your water? Then, what can you do about it?

What are Tannins?

Tannins are frequently and naturally in surface water bodies such as lakes and rivers. It is decayed organic material from plant or animal. It dissolves into water. It basically is a natural, organic fermentation. Tannins are more common in swamps, marshes and coasts. They can also form in wells.

Possible signs of tannins include:

  • Yellow or brown color to the water. It looks sort of like tea.
  • Yellow discoloration in toilets, sinks and fixtures.

    What does Tannins in Water Mean?
    Tannin will give a yellow or brown color to water.
  • Yellow stains on laundry after it’s been washed.
  • Water has a musty odor.
  • Water tastes bitter, metallic, tart or sour.
  • You might test your water for another reason and find a high level of tannins.

Are Tannins Harmful?

Tannins can be ugly and nasty. They are not a health problem or hazard in water. If you find tannins in your primary water source, though, it could be an indication of more contaminates or particulates. If tannin has gathered in your well or water supplier, it could mean other matter has or could get into it, too. If you’re testing for tannins, it’s likely smart to test for bacteria or other pollutants.

How Did Tannin Get into my Home’s Water?

The EPA considers tannins as a secondary contaminant. This means there are no requirements or regulations about removing tannins. The matter can get into water which is sent into homes. Tannins can seep into wells.

What Does Tannins in Water Mean?

Thankfully, there are no health problems connected to tannins in water. Most of the issues related to tannins in water are nasty, but not actually harmful. It will make your water unpleasant, including to drink, so it will be important to solve the problem.

Other issues may be discoloring and staining bathroom and kitchen fixtures and staining laundry as it runs through a washing machine.

Nonetheless, high degrees of tannins in water can be an indication that other kinds of impurities may be present in your water. If tannins had the ability to make it past water treatment systems and right into your home water supply, there’s a more likely chance that contaminants like bacteria could be in your water as well. If you believe that your residence’s water could consist of tannins, be sure to have it tested by a water quality expert.

How Do I Get Rid of Tannins in My Water?

Tannins can be easily removed from water by putting in a water filtration system. Carbon filtering has actually proven to be very effective at eliminating tannins. We suggest setting up an entire system with your home plumbing to filter out tannins, because that will solve the smells, tastes, odors and avoid staining of your plumbing fixtures and clothing.

If a whole home system does not currently fit your plans or capabilities, a point-of-use filter system will at least get rid of tannins from one tap and give you accessibility to clean, clear, odor free and great-tasting water.

There are several options for eliminating tannins, depending upon the tannin level in your water.

  • Carbon filters
  • Anion exchange
  • Chlorination and extra filtration

If you’re unsure about having tannins in your water, contact a professional expert to discuss your water testing and treatment choices.

Can I Test Water for Tannins?

Yes, you can. Tannins produce a light yellow to dark brown discoloration in water. An easy, quick test for tannins is fill a clear glass with water, let it sit overnight or for a few hours. If the water is still discolored evenly in the glass, it is probably containing tannins. If the color has settled to the bottom of the glass, it’s probably from another mineral or substance such as iron or manganese.

You may additionally need to test your home water for other contaminants such as sulfates, alkalinity, iron, total dissolved solids (TDS) and hard water. Doing these tests might help you figure out which treatment methods will be best for your circumstances. There’s one more test for checking for tannins and iron together. Iron can produce a false positive result for tannins, so you need to rule out iron or tannins to make sure about what’s contaminating your water.


South End Water Filtration specializes in HALO Water Filter products including the HALO H2 Zero Whole Home Water Filter. We’re just a click away to help and answer any questions. South End Plumbing and South End Water Filtration will give you a free estimate. Call us at 704-486-1988 or contact us online to schedule a visit.