Thanks Frank- I didn't think of that. I will call the city and tell
them about the problem. .
Frank K. wrote:
Take a sample to the city water dept. or call them to come
to your house to analyze the water.

Frank

wrote in message
oups.com...
I took the advice of someone on this forum and unscrewed
the line at
the bottom of the toilet and flushed out the line into a
bucket. I
probably flushed out about 20 gallons of water. With each
fill of the
bucket there were black rocks{iron sulfide?} although less
as i flushed
out more water.My original problem was the toilet wouldn't
stop. I
discovered these rocks were under the rubber seal in the
Fluidmaster,preventing the toiulet from stopping.I have
copper lines so
i don't think it could be a corrosion problem. Could these
rocks be
coming through the city pipes? If so, how would they be
able to keep it
from coming through my lines?