I'm trying to convert a dining room to a bathroom. In doing so, I have put in new PVC plumbing for the drains and I am in the process of installing new copper plumbing for water supply.

Yesterday, I cut the copper main line and soldered in new fittings etc for the cold water supply to the new bathroom. I did all of this OK.

However, this job afforded me the opportunity to look inside the existing copper plumbing, and there was a gross green slime layer. I would possibly like to flush this out.

Questions:
1. Is it necessary to flush it out?
2. If so, what is the best way to flush out the system?

Thanks,
Tim

You must be referring to the old copper where you tied in the new pipes. Just the tarnishing of the copper. Don't worry about it unless you want to replace all of your piping.

Almost every square inch of used cooper pipe will be green on the inside. Let it be. You would load your pants if you saw the inside of an old galvanized pipe.