Green Brita Filter Water – What Is It And Is It Harmful?


Brita filter water may turn green because of algal growth caused by not washing your pitcher enough, using well water, or leaving your pitcher in direct sunlight. Do not drink algae contaminated water – scrub the pitcher with white vinegar and water before using it again. If algae are observed on the filter cartridge, it should be discarded and replaced immediately.

Brita’s filter pitchers are a great addition to your home. They drastically improve the flavor and odor of water, making it taste great. If you find unusual green slime in your filter water, however, it indicates a big issue – algae.

Finding algae in your filter pitcher may be concerning but can be rectified with a few simple steps. In this article, I take you through the common causes of green water, and how you can resolve it.

Why Your Brita Water Is Green

The green color in your Brita filter water indicates the presence of algae, usually cyanobacteria.

Algae are plant-like bacteria that grow in moist environments. They are usually found in ponds, lakes, tanks, wells, and streams.

But what are algae doing in your filter in the first place? Algae may thrive inside your Brita filter if you don’t clean it often, or if your water is not treated with chlorine.

When water is contaminated with algae, it will form a slimy green layer at the base and sides of the pitcher. It may also turn the water green.

Bacteria and algal spores are found everywhere in the environment. They are mostly harmless, until they find a suitable medium to grow – such as a water filter.

If you don’t clean your pitcher regularly, it becomes susceptible to algal growth.

Leaving your pitcher open or exposing it to too much sunlight can also contaminate the water with these spores.

An open/leaky pitcher left in warm temperature presents an optimal environment for algae, mold, and mildew to grow.

If your primary water supply is tap water, it will usually be treated with chlorine before it reaches your home.

Chlorine is a disinfectant that reduces the growth of bacteria and algae.

However, once this water passes through the Brita filter, the concentration of chlorine is dramatically reduced. This leaves your water open to contamination in the pitcher.

If you notice algae in the water even after regularly cleaning your pitcher, your tap water may be contaminated with algae before it reaches you. Check your water supply and test for contaminants.

What about well water?

Brita filter pitchers are not designed to purify well water. Brita filters primarily remove the taste and odor of chlorine in the water.

Private well water (and non-regulated water supply sources) is usually not treated with chlorine beforehand, and is vulnerable to algal and bacterial growth.

Wells provide the optimal environment for algal growth because they are damp and warm. When well water is passed through a Brita filter, the algae is not removed.

So when the water settles in the pitcher, the algae already present in the water propagate and ‘bloom’ to form a slimy green layer.

Will green water taste or smell bad?

Green water smells musty and tastes moldy. If the water is contaminated with bacteria (in addition to algae), it may smell like rotten eggs. This indicates the presence of hydrogen sulfide, which is released as a by-product of bacterial activity.

Water contaminated with algae and bacteria is not safe for consumption.

While some algae may not harm you, most can cause nausea, stomachache, diarrhea, and vomiting. You may also contract nasty stomach bugs from drinking contaminated water.

Ingesting too much blue-green algae can also cause skin irritation, fever, and gastroenteric problems.

How green water affects your filter

If the algae have only contaminated your pitcher, it is easy to get rid of. However, if you suspect algae have contaminated your filter cartridge, you will need to replace it with a new one.

Do not use cleaning agents or detergent on your filter. It is best to discard the filter and use a new filter after thoroughly washing the pitcher and lid.

How To Stop Your Brita Filter Water Turning Green

Here a few steps you can follow to prevent algal contamination in your Brita filter:

  1. Wash your hands before handling the pitcher. Use soap and wash your hands for 20 seconds before handling your pitcher.
  2. Clean the pitcher and lid regularly – at least once a month.
  3. We also recommend washing the pitcher and lid every time you replace the filter.
  4. Keep the spout of the filter clean. Make sure the spout is sealed tightly after use.
  5. Do not drink directly out of the pitcher. Pour the water into a glass. Putting your mouth on the spout may contaminate the pitcher.
  6. Keep your pitcher away from direct sunlight, because it encourages algal growth. A cool, dark place is ideal. You can leave the pitcher inside the refrigerator too.
  7. Replace the filter frequently, according to manufacturing instructions. The Brita Standard filter must be replaced every 2 months, while the EliteTM filter must be changed every 6 months.
  8. Keep the Brita filter cartridge sealed before use. Store it in a cool, dry place.
  9. Do not use water over 38°C/100°F inside a Brita pitcher filter.
  10. Do not use well water in a Brita filter.
  11. If you’re looking for a more comprehensive solution to algae and mold in your home, you might want to invest in an air purifier.

How To Clean Your Brita Filter

To clean your Brita filter, follow these simple steps:

  • First, pour out any water and remove the filter.
  • Take the pitcher apart to separate the pitcher and lid.
  • Wash the pitcher and lid with mild detergent and water.
  • If you find green slimy deposits, scrub them clean with a mixture of white vinegar and water. Make sure to reach every crevice with a brush.
  • Rinse the pitcher and lid thoroughly after soaking it in lukewarm water.
  • Dry the pitcher and lid with a cloth. Reassemble the pitcher ONLY after all the components are dry.
  • Fit the new filter, screw it in, and pour out some water until the black carbon specks disappear.

Frequently Asked Questions

Why Is There Algae In My Brita Pitcher?

Algae can grow in a Brita pitcher due to two reasons – your water may already be contaminated by algae before you pour it in, or spores may grow from the environment.

If your well water (or untreated tap water) is contaminated with algae, it may show up in your pitcher as green slime. If you do not clean the pitcher regularly or leave it in direct sunlight, the warmth and moisture can encourage algal growth.

Leaving your pitcher open in warm weather can cause algal blooms too.

Are The Algae In My Brita Filter Harmful?

It is not recommended to drink algae-contaminated water. Although ingesting a small amount of algae may not be harmful, you might experience symptoms like nausea, diarrhoea, vomiting, headaches rashes, and stomachaches.

Water contaminated with algae does not smell or taste good either.

If your primary source of water is from a private well, we recommend using a more thorough method of purification before passing it through a filter pitcher.

Can Brita Filters Get Moldy?

Brita filters can develop mold and mildew if you leave them out in direct sunlight for too long. Not sealing the spout properly, using well water, and not cleaning the pitcher regularly can also cause mold to grow.

If you don’t clean the filter pitcher sufficiently, the mold and algae may also migrate to the filter cartridge. In this case, we recommend discarding the cartridge, cleaning the pitcher thoroughly, and fitting a new one.

Russell Singleton

Russell has a Bachelor of Science (Environmental and Marine Geoscience) with Class I Honors. He is currently completing his doctorate in science and is passionate about all earth processes, especially isotope geochemistry and paleohydrology.

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