DIYbanter - View Single Post - Still have black crystals floating around in toilet

wrote:
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?

Sure. Could be coming upstream from some supply
pipe repair or the water company flushing the
system, or some idiot homeowner that is allowing
stuff to siphon into the system.

The question is what are they "little black
rocks?" How big? less than 1/16" 1/16"-1/8",
etc. Soft or hard? Do they crush into a powder?
Your best bet is to contact your water company and
ask.