Why is my water cloudy or milky?
Cloudy or milky water is usually just harmless dissolved air — but it can also be sediment or, rarely, methane. There is an easy way to tell.
The likely causes
Cold or pressurized water holds tiny air bubbles that make it look milky, then clears from the bottom up as the bubbles rise. Completely harmless.
Fine particles of dirt, rust, or minerals stay suspended and make water look hazy — more common after pipe work or in well water.
In some well water, dissolved methane causes persistent cloudiness and needs venting — uncommon, but worth ruling out.
Is it dangerous?
The overwhelmingly common cause — air — is completely harmless. Sediment is an aesthetic nuisance. Only methane (rare, well-specific) is a safety concern, and it does not clear like air does.
How to tell what it is
Fill a clear glass and watch it. If it clears from the bottom upward within a minute or two, it is just air — nothing to fix. If it stays cloudy or has settling particles, it is sediment.
The fix
If it is air, do nothing — it is harmless. If it is sediment, a sediment pre-filter or whole-house filter clears it; an under-sink filter handles it at the drinking tap.
If the cloudiness clears from the bottom up, it is dissolved air and a filter is unnecessary — you would be buying a filter to solve a non-problem.
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