black residue

Replaced drain in the bathroom sink, when we turn the water on there was black residue initially. Thought it might Might be because we hit the braided supply hoses. When we turned the water back on and jiggled the hoses we would get black residue out of Hot and cold. Information?

At two occasions I saw black residue coming out off the bathtub faucet. It was a black soft residu about the size of a match head. It was easy to clean my fingers only under water after rubbing it between my fingers. It was not smelling anything. Here is a video : What is it? Can it be the...

I had my bathroom sink replaced a few months ago. When he firs turned on the water, it was all black. After running the water it appeared clear, and continues to appear clear to the naked eye. But to this day black residue collects in the bottom cracks of the paper cups I use. This did not...