Black residue on all faucets.
We are on city water. The house is circa 1980. We have noticed there is a black residue on the faucets throughout the house. It also builds up in the toilet. The black residue can be cleaned off easily with a sponge and water.
I am now finally getting around to purchasing a water quality tester and at least get a kitchen under counter filter for drinking water. The only filter we have in the house is the water dispenser in the refrigerator which dispenses too slowly for my precious time.
Does anyone know what this is and if I should look more into a whole house filter? Is there a specific water tester I should purchase?
Thanks in advance.