re: DIY PEX pipe installation and replacement of steel pipe

I just got through doing a PEX (Uponor/expansion) re-pipe of my entire house, well...almost done, to replace the old galvanized steel pipe. There were times through the process where I was turning the main water supply on and off again since I kind of replaced it in phases to keep running water most of the time. In doing this, our kitchen sink, which had decent pressure before, all the sudden got noticeably worse (still connected at that time to galvanized pipe). Figured it would get better in a few weeks once I had replaced the pipe to PEX to the sink. But it did not. Even when connected to PEX. I cleaned all the screens and there was noticeable rust in them but it did not improve the pressure.

I ended up disconnecting the flexible supply hoses under the sink (both hot and cold) at the valves and put those ends into a bucket. With the screen and aerator removed, I took my air compressor and shot air at the faucet down into the bucket. Sure enough, chips of rust shot out and pressure was good again.