Why does my water have black specks in it?
Black specks usually come from one of three places: manganese, a deteriorating rubber part, or the carbon media from a failing filter.
The likely causes
A naturally occurring mineral that oxidizes into black specks and stains, often alongside iron in well water.
Hard, black, rubbery specks often mean a rubber gasket, hose, or supply-line washer is breaking down — usually from hot water or chloramine attacking it.
Loose black granules right after installing a new carbon filter are harmless carbon dust — but ongoing black grit can mean the filter is failing and needs replacing.
Is it dangerous?
None of these are typically a health hazard, but a failing filter is defeating its own purpose — so black grit from a filter means it is time to replace it, not ignore it.
How to tell what it is
Press a speck: hard and rubbery = plumbing rubber; gritty and it stains = manganese; light granules right after a new filter = carbon fines. If it started when you changed a filter or hose, that is your source.
The fix
For manganese, a whole-house oxidizing/sediment filter removes it. For rubber, replace the failing washer, hose, or gasket. For a shedding filter, replace the cartridge — and flush a new carbon filter before first use.
Also searched: black particles in water · black flecks in tap water · black bits in water · black sediment