Quick Answer:
Cloudy or milky water right after changing a filter is often tiny air bubbles or disturbed sediments. Try a simple glass test and a few quick checks. If the cloudiness doesn’t clear, leaves residue, or shows up at multiple fixtures, have a plumber test the source safely.
Why This Happens
- Air introduced during filter replacement can make water look milky; bubbles usually rise and clear in a minute.
- A loose or disturbed filter can release tiny particles or trapped sediment into the lines.
- Differences between hot and cold water behavior can point to the source: tank or heater issues vs supply-side air or debris.
Step-by-Step What to Do
1. Do a quick glass test
Fill a clear glass from the affected tap and set it on a level surface. Watch for up to one minute. If the cloudiness rises from the bottom and clears from the top, that’s usually trapped air. If it stays cloudy or leaves a film, that suggests particles or minerals.
Tip: If the glass clears quickly, see Milky water in glass but clears quickly for more detail on what that pattern means.
2. Compare hot and cold taps
- Run the cold tap into a glass, then the hot tap into another. Note which is cloudier.
- If only hot water is cloudy, the problem may be the water heater. If cold or both are cloudy, it’s more likely the filter, incoming supply, or air in pipes.
- If cloudiness appears only in the shower, check shower-specific parts and see Milky water in shower only for context.
3. Check aerators and shower heads
- Unscrew faucet aerators and the shower-head face. Look for white specks, flakes, or trapped air bubbles.
- Rinse or brush the screens gently and run water briefly to see if particles stop appearing.
4. Inspect the filter installation
- Turn off the water supply briefly and confirm the filter is seated and sealed correctly. A poor seal or loose fittings can let air or debris into the line.
- Reinstall per the filter instructions, then run water for a short time to clear the line.
5. Short, controlled flush — don’t overdo it
- Run the affected tap for a minute or two to clear trapped air or loose particles. Keep this brief; avoid repeatedly flushing the water heater or running long continuous flushes without guidance.
- After flushing, do the glass test again to confirm clarity.
6. Monitor and document
- Note which fixtures are affected, how long the cloudiness lasts, and whether any residue or odor appears.
- If the issue returns or other signs appear (staining, persistent residue), record times and conditions to share with a professional.
What Not to Do
- Don’t assume all cloudiness is harmless air or start flushing the heater repeatedly; if cloudiness persists or leaves residue, have a plumber inspect the system.
- Don’t use strong chemical cleaners inside plumbing to try to “clear” cloudy water — that can cause damage or introduce contaminants.
- Don’t ignore cloudiness that appears suddenly across multiple fixtures or that changes taste or leaves deposits.
When to Call a Professional
- Call a plumber if cloudiness persists after the checks above, affects several fixtures, or leaves residue or film.
- A plumber can safely test whether the issue is air, sediment, mineral content, or a failing component (filter, cartridge housing, or heater).
- If you notice discoloration, an odd odor, or staining on fixtures, contact a professional promptly.
Safety Notes
- Turn off water at the valve before removing filter housings or aerators to avoid spills and water damage.
- Use a cloth when handling aerators or filter parts to prevent small pieces from dropping down the drain.
- If you smell gas or detect a strong chemical odor, stop and contact professionals; don’t try to troubleshoot those hazards yourself.
Common Homeowner Questions
- Why did this happen right after I changed the filter? Small amounts of air or loose particles often enter the line during filter changes; those typically clear with a short flush or a minute in a glass.
- How long should I wait to see if it clears? Give the glass test up to one minute; most air-related cloudiness clears quickly. Monitor taps for a few hours after initial flushing.
- When is water unsafe to use? If cloudiness leaves residue, has an odd odor, or is accompanied by discoloration, avoid drinking and call a plumber to test the supply.