Cloudy Tap Water: Causes, Safety & When To Worry

That milky, cloudy water coming from your faucet is almost always harmless. In the vast majority of cases, cloudy tap water is caused by tiny air bubbles—not contamination. The telltale sign: if the water clears from the bottom up within 30 seconds, it's just air.

This guide explains why your water looks cloudy, how to tell if it's safe, and when you should actually be concerned.

The 30-Second Glass Test

Before you worry, try this simple test:

1. Fill a clear glass with cold tap water
2. Set it on the counter
3. Watch for 30 seconds

If the water clears from the bottom up: It's air bubbles. Completely harmless. The bubbles rise to the surface and escape into the air, leaving clear water behind.

If the cloudiness stays or settles to the bottom: You may have sediment, hard water minerals, or another issue worth investigating.

This test works because air bubbles rise, while particles sink or stay suspended. It's the fastest way to determine if you have a real problem or just aerated water.

Why Does Tap Water Turn Cloudy?

1. Air Bubbles (Most Common)

The most frequent cause of milky water is simply dissolved air escaping from the water. According to the U.S. Geological Survey, this is "completely harmless" and happens because:

• Pressure changes: Water in your pipes is under higher pressure than the air in your glass. When you open the tap, that pressure drops and dissolved air comes out of solution—similar to opening a carbonated drink.
• Cold weather: Cold water holds more dissolved oxygen than warm water. During winter, water traveling from cold reservoirs warms up on its way to your tap, releasing excess air as tiny bubbles.
• Water main work: After repairs or maintenance, air can get trapped in municipal pipes. This typically clears within a day or two.

Cities like Seattle and Denver, which draw water from cold mountain reservoirs, often see more reports of milky water during winter months.

2. Hard Water Minerals

If cloudiness doesn't clear after a minute, you might have hard water. This occurs when water contains high levels of dissolved calcium and magnesium.

Hard water cloudiness:

• Doesn't clear up over time
• May leave white residue on glasses and fixtures
• Often comes with other signs like soap scum and dry skin

Cities with very hard water—like Phoenix (285 ppm), San Diego (275 ppm), and Miami (225 ppm)—are more likely to experience mineral-related cloudiness.

3. Sediment or Particles

Less commonly, cloudy water can contain:

• Sand or silt: Especially in well water or after construction nearby
• Rust particles: From corroding pipes (often has a slight orange or brown tint)
• Calcium carbonate flakes: From deteriorating water heater dip tubes

Sediment-caused cloudiness usually settles to the bottom of the glass rather than rising to the top.

4. Methane Gas (Well Water Only)

If you're on a private well and your water looks effervescent or bubbly with a slight odor, it could contain dissolved methane. This is more common in areas with natural gas deposits or near fracking operations.

Methane in water isn't toxic to drink, but it can be a fire hazard if it accumulates in enclosed spaces. If you suspect methane, have your well water tested.

Is Cloudy Tap Water Safe To Drink?

Yes—in most cases, cloudy water is perfectly safe.

Here's the breakdown by cause:

Cause	Safe to Drink?	Action Needed
Air bubbles	✅ Yes	None—just wait for it to clear
Hard water minerals	✅ Yes	Consider water softener for home comfort
Sediment (sand/silt)	⚠️ Usually	Filter recommended; test if persistent
Rust particles	⚠️ Usually	Identify source; test for lead in older homes
Methane (wells)	✅ Yes to drink	Ventilation important; professional assessment

The key exceptions are when cloudiness is accompanied by:

• Unusual color (brown, green, yellow)
• Strange smell (rotten eggs, musty, chemical)
• Off taste (metallic, bitter, salty)

These warning signs suggest something other than air or minerals, and you should avoid drinking the water until you identify the cause.

Cloudy Hot Water vs. Cold Water

Only Hot Water Is Cloudy

This is extremely common and almost always harmless. Hot water holds less dissolved air than cold water, so when your water heater warms up the supply, the excess air releases as bubbles.

If only your hot water is cloudy:

• It's normal—air is escaping due to heating
• The water is safe
• No action needed

Only Cold Water Is Cloudy

If just your cold water appears milky:

• Check if it clears with the 30-second test
• It may be caused by recent utility maintenance
• If persistent, contact your water provider

Both Hot and Cold Are Cloudy

This typically indicates:

• A municipal water system issue (often temporary)
• Air in your home's main water line
• Possible sediment if it doesn't clear

How To Fix Cloudy Tap Water

For Air Bubbles

Honestly? You don't need to fix it. Air bubble cloudiness:

• Clears on its own within seconds
• Doesn't affect taste or safety
• Is completely harmless

If it bothers you aesthetically, simply fill a pitcher and let it sit for a minute before drinking.

For Hard Water

Hard water requires treatment to address:

1. Water softener: Removes calcium and magnesium through ion exchange. Whole-house systems cost $500-2,500 installed.
2. Reverse osmosis: Point-of-use systems for drinking water. More affordable at $150-500.
3. Water conditioner: Doesn't remove minerals but prevents scale buildup. Less effective for visible cloudiness.

Check your city's water hardness levels—if you're in Los Angeles (178 ppm), Chicago (143 ppm), or other hard water areas, a softener may improve your water clarity significantly.

For Sediment

• Flush your pipes: Run cold water for 5-10 minutes to clear any disturbed particles
• Clean aerators: Unscrew faucet screens and rinse out accumulated debris
• Install a sediment filter: Whole-house filters ($50-200) catch particles before they reach your taps
• Flush water heater: Annual maintenance prevents sediment buildup

For Well Water Issues

• Test annually: Check for bacteria, sediment, and minerals
• Inspect well cap: Ensure it's sealed to prevent surface water intrusion
• Consider UV treatment: Kills bacteria if testing reveals contamination
• Install appropriate filtration: Based on your specific test results

When To Contact Your Water Utility

Call your municipal water provider if:

• Cloudy water affects your entire neighborhood
• Cloudiness persists for more than 24 hours
• You notice unusual odor or color along with cloudiness
• There's been recent construction or main breaks nearby
• Water pressure changes dramatically with the cloudiness

Most utilities have water quality hotlines and will investigate persistent issues. Many offer free water testing for residents.

Cloudy Water in Specific Situations

Cloudy Water After Vacation

If you return home to cloudy water after being away:

• Run all taps for 5-10 minutes to flush stagnant water
• Flush toilets several times
• Check that your water heater is functioning properly

Water sitting in pipes can accumulate dissolved gases and sediment. Flushing restores normal clarity.

Cloudy Water in New Home

New construction or renovated plumbing often has:

• Air trapped in new pipes
• Flux residue from soldering (usually clears quickly)
• Sediment from installation

Run your water system thoroughly—it typically clears within a few days of regular use.

Cloudy Ice Cubes

If your ice looks white or cloudy but your water is clear:

• This is normal—it's caused by trapped air and minerals freezing
• Commercial ice is clear because it's frozen slowly and filtered
• Cloudy ice is safe; it just doesn't look as nice

To make clearer ice at home, use filtered water and freeze it slowly (insulated container with top open).

Cloudy Water vs. Other Discoloration

Not sure if your water is cloudy or something else? Here's how to tell:

Appearance	Likely Cause	Concern Level
Milky/white (clears quickly)	Air bubbles	Very low
Milky/white (doesn't clear)	Hard water minerals	Low
Hazy with particles	Sediment	Low to moderate
Brown or rust-colored	Iron, rust, sediment	Low (aesthetic)
Yellow or orange	Iron, tannins	Low
Green or blue tint	Copper corrosion	Moderate—test recommended
Black specks	Manganese, gasket deterioration	Low to moderate

If your water has color rather than just cloudiness, see our guide on brown tap water.

Frequently Asked Questions

Why is my tap water suddenly cloudy?

The most common reasons for sudden cloudiness are:

• Recent work on municipal water mains
• Cold weather (more dissolved air in cold water)
• Changes in water pressure
• A burst pipe or repair in your area

In almost all cases, it's just air and will clear within seconds when you let the water sit.

Can cloudy water make you sick?

Cloudy water caused by air bubbles or hard water minerals will not make you sick. However, if cloudiness is accompanied by unusual color, smell, or taste, avoid drinking it until you identify the cause. Persistent cloudiness with other symptoms could indicate bacterial contamination, especially in well water.

Why does my water look cloudy only in winter?

Cold water holds more dissolved oxygen than warm water. During winter, water from cold reservoirs contains more dissolved air. As this cold water travels through pipes and warms slightly, the excess air comes out of solution, creating temporary cloudiness. This is normal and completely harmless.

Should I buy a filter for cloudy water?

If your cloudiness is caused by air bubbles (clears in 30 seconds), no filter is needed. If it's caused by hard water or sediment, a filter or water softener can help. Test your water first to determine the cause before investing in treatment.

How long should I wait for cloudy water to clear?

Air bubble cloudiness should clear within 30-60 seconds. If water remains cloudy after several minutes, you may have hard water, sediment, or another issue. Water that's still cloudy after 24 hours warrants a call to your water utility or a professional water test.

Check Your City's Water Quality

Wondering about water hardness and quality in your area? We track data for thousands of US cities:

Cities with soft water (less likely to see mineral cloudiness):

• Seattle, WA – 22 ppm (soft)
• New York City, NY – 35 ppm (soft)
• Portland, OR – 28 ppm (soft)

Cities with hard water (may see mineral-related cloudiness):

• Phoenix, AZ – 285 ppm (very hard)
• San Diego, CA – 275 ppm (very hard)
• Las Vegas, NV – 290 ppm (very hard)
• Miami, FL – 225 ppm (very hard)

Search your city →

Sources: U.S. Geological Survey (USGS), EPA Secondary Drinking Water Standards. For the most current information about your specific water supply, contact your local water utility.