Grey/white spots on the bottom of a Brita filter, possibly mold? : r/whatisthisthing

Black stuff in Brita pitcher? : r/CleaningTips

Black stuff in cat's water fountain…mold or from filter? : r/cats

What is this ring in my toilet? Shows up after a week or two even in toilets that we purposely haven't used. : r/HomeImprovement

In my Brita filter this white stuff kinda appeared outa nowhere and the water looks dirty. What is this? : r/whatisthisthing

What are these white cottony balls found in my faucet's aerator? : r/ whatisthisthing

Grey/white spots on the bottom of a Brita filter, possibly mold? : r/ whatisthisthing

Does this look like mold in my tea kettle or just burns? ( NOT asking for ID just is it mold or not ) : r/Mold

Brown flakes coming from water filter. We changed the water filter a few weeks ago yet some flakes still come out? What could this be? : r/ whatisthisthing

Drank from my Brita filter only to realize there was algae growing on the bottom. Will I be okay? : r/HydroHomies

What is inside our electric kettle? : r/tea