Whole House Water Filter Turns Brown: 5 Causes And Fixes

Clean and clear water is necessary for your home no matter the use, as contaminated water is unpleasant and causes ailments. Installing a whole-house water filter is an excellent way to combat impurities. These filters are connected to the main water line and clean all the water entering the home.

Whole-house water filters clear discolored water, but they, too, can become brown over time. When the filters turn brown, it’ll lead to brown water across different faucets in your home. A discolored filtration unit makes the filter inefficient as it will always produce brown water, which is unpleasant. Depending on the cause, brown water may be smelly, unpleasant to drink, and unsightly, but not harmful in small quantities.

This guide discusses the many causes of house filters turning brown and ways to tackle this problem. First, you must understand the reason, as it’ll determine the most efficient solution to employ.

Causes of Whole-House Water Filter Turning Brown

Causes of Whole-House Water Filter Turning Brown

Why do whole-house water filters turn brown? The system is set up to clean water and remove discoloration that can stain the filter. To fix this issue, check out some common causes of brown whole-house water filters.

1. Buildup of Contaminant

Whole-house water filters block contaminants in their filters as clean water passes through them. Over time, this buildup can cause the filter to turn brown or black and is one of the primary causes of a discolored filter unit.

The buildup of contaminants in the filtration system is a normal process and will occur after using the filter for a long time. When this happens, it shows the filter has been removing impurities and may be past its usefulness. Clogging of the filter pores is another problem that typically accompanies the buildup of contaminants.

2. Manganese

Manganese is a naturally occurring trace mineral essential to our body’s functionality. It helps with our body’s functionality in small amounts but is a leading cause of brown whole-house water filters when found in larger quantities in the water source. They are naturally present in the soil and rocks from where it enters the groundwater.

When your whole-house filter continues to remove manganese over time, it is deposited inside, turning it brown. Manganese produces black slime that discolors the filter. This trace mineral often occurs with other minerals like iron.

3. Iron And Rust

The presence of manganese in your water is a massive indication of iron and rust. While iron is also an essential nutrient, it can cause filter discoloration in high quantities. Iron causes rust on exposure to oxygen, activated when high iron content deposited in the pipes and filter unit comes in contact with the oxygen in the water.

While not all iron types have the staining ability, here are a few that do:

  • Iron bacteria: some microscopic bacteria in water combine with iron for survival and are iron bacteria. They can turn your whole-house water filter brown while leaving slimy deposits along the waterway.
  • Ferric iron: if your primary water source looks reddish, it may be due to the presence of ferric iron. This type of iron is commonly found in water and is reddish brown.
  • Ferrous iron: unlike ferric iron, ferrous iron is clear and colorless when dissolved in water. However, when exposed to air, it becomes cloudy with traces of reddish-brown substances in the water. Ferrous iron will typically make the water have a metallic taste.

Homes that use well water as the primary water source and old pipes are more susceptible to rust. Water flowing through rusted pipes will pick up flakes from the pipes and deposit them in the filter, which may absorb its brown color.

4. Sediment

Sediments in your water, like soil and silt, can quickly enter groundwater and into your whole-house water filter. These impurities can change the water brown, staining your filtration unit.

Areas with land construction nearby, high erosion levels, and general disturbances to the soil are prone to silt and other sediments in their water. Silt-laden water has an unpleasant taste, can be cloudy, and with a brown color. Residues are usually minimal in water but can build up in pipes over time.

Other sediments like smoky quartz or black sand found in volcanic areas can enter the water and cause discolored specks in the filtration system. The build-up happens gradually; in the case of a sudden color change, it may indicate an infiltration by a new water source, like rainfall.

5. Tannins

Tannins are organic substances naturally found in plants’ leaves, bark, and stems. They can enter water from low-hanging branches, fallen trees, or organic matter.

The color of water exposed to high tannins ranges from yellow to red, with the discolored water entering the filter and staining the unit. Tannins are not harmful but will discolor water, stain filters, and have an unpleasant taste.

How to Fix Brown Whole-House Water Filter?

How to Fix Brown Whole-House Water Filter?

Knowing why your whole-house water filter turned brown is insufficient. You must fix the issue to continue getting clear water in your house. If you noticed your filter unit is stained brown, here are ways to fix this problem:

1. Test The Water

Instead of guessing the cause of the brown filter, it is best to do a water test and discover the culprit. By testing the water, you find out the impurity staining the filter and can now choose a suitable way to solve it. Water tests typically check the contaminants present and their quantities.

If your water source is from a public utility, you can get a free water report with a detailed water test. For private sources, you can employ the services of professionals or run the test yourself using DIY test kits.

2. Replace Filter

Brown whole-house water filters have often worked diligently and are past their life cycle. Browning caused by the natural buildup of contaminants does not require a particular procedure. Replace the filter with a new system.

Filters lose efficiency over time, so they may have lost most of their filtration capacities by the time it has turned brown due to the usual build-up of impurities. You can replace the filter using simple DIY guides.

3. Install Additional Filters

After testing the water, you may have discovered a high amount of contaminant not covered in the whole-house water filter. You should fix additional filters to the system to remove these impurities. The type to add will depend on the contaminant present in the water.

Sediment filters

Browning caused by sediments like algae, soil, and silt will require a sediment filter to remove them. The filter will remove the residues and stop the browning process. The best place to add residue filters is right after the pressure tank on the main water line before any pre-filter units.

Sediment cartridge filters and spin-down filters are the common types of filters to add to remove sediments. Smaller sediments require sediment cartridge filters, while more significant deposits require spin-down systems.

Iron and manganese filters

Iron and manganese are usually present together in water. You can remove these minerals using the same filtration system. MDF and similar media will remove mild traces of these minerals in the water.

You may require a chemical or air injection system where the concentration is higher. Chemical injection inhibits the growth of iron bacteria.

Tannins filter

Ion exchange and reverse osmosis filters are popular options for removing tannins from water. Ion exchange that uses acrylic or styrene-based chlorine resin is the most efficient filter for tannins.

4. Replace Rusted Pipes And Water Heaters

Changing these fixtures is necessary when flakes from rusted pipes and water heaters cause brown filters. Replace all rusted pipes and water heaters to stop the staining. The replacement may be expensive, depending on the size of the rusted fixtures.

5. Use a Water Softener

Water softeners work differently from filters, exchanging ions in the water with sodium. It is excellent for moderate cases of minerals in the water in addition to their filters. Water softeners prevent impurities from binding to the surface of fixtures, which can cause buildup or rust.

How to Prevent Whole-House Water Filter From Turning Brown?

How to Prevent Whole-House Water Filter From Turning Brown?

Some methods for fixing brown whole-house water filters are time-consuming and expensive. It is best to adopt ways to prevent a recurrence. Here’s how to do this:

  • Replace filters regularly: You’ll prevent the filtration unit from turning brown if you change the system before it is due. You should find out how long the whole-house water filter lasts to get an idea while also observing the system for signs of depreciation.
  • Clean the filters regularly: You remove any buildup before it stains the unit if you clean the filters frequently. Cleaning the filter also helps to unclog the unit and remove offensive odor and unpleasant taste in the water.
  • Test your water annually: Annually testing the water’s ph, dissolved solids, nitrate, and bacteria level is vital. This will help you stay updated on any change in impurities in your water.
  • Install all the necessary filters: Run a water taste and install all the essential filters to remove minerals and deposits.


Here we highlight popular questions about brown whole-house water filters with their answers.

Is brown water safe to drink?

Brown water is typically safe to drink but is unpleasant and may have a metallic taste. Also, the safety of brown water depends on the cause, as high levels of iron and manganese in water are hazardous.

Why does my whole-house filter turn brown?

Iron and manganese, residues, tannins, and normal buildup of contaminants can cause whole-house water filters to turn brown.

Can city water turn a water filter brown?

Although rarely, since essential filtration is carried out before channeling to homes. City water can turn your water filter brown, and this is often due to corroded infrastructure.


Whole-house water filters are meant to clean your water, but the possibility of getting clear water diminishes when it becomes brown. Organic deposits, tannins, iron, and manganese are widespread causes of brown filters.

Fixing this problem requires accurately identifying the cause, which can be found by testing the water. Install the correct filter, replace old filters, and add water softeners to fix brown whole-house water filter problems.