Water Pressure now low

I needed to solder a new copper line to an existing cold water line in the master bath.
I used an air compressor to blow out the lines and kept the pressure less than 50 pounds.
Examination of the inside of the original 1/2 line looked pretty clean
After soldering the line and turning the water back on,
I noticed the water pressure was low in the guest bath (master bath still under construction).

For example, the Washer pressure seemed OK.
However, the bathroom toilet, sink and tub were quite low.

The washer is located in the guest bathroom as is the toilet, sink and tub that had low pressure.
I did find mineral deposits (white hard) after:
1) Removing the flowmaster from the toilet.
2) Taking apart the bathroom sink faucet and stop cock.
3) The bathtub cold initially had virtually no flow.
I then took apart the the bathtub value (old PP faucet) and blew the cold line from the PP value with the
cold water line from the washer disconnected. Got a small handfull (estimate < 1/8 cup) of mineral deposits.

Everything appears to be clean now (no mineral deposits in sink screen or in Fludimaster) and tub flow has improved
but still not what it used to be.

Have checked the water meter with everything turned off and needle does NOT move so assuming no leaks (I HOPE).

Any suggestions how to proceed?

Did you take the aerators off the faucets? Sounds like you have fairly hard water...mineral deposits are to be expected unless treated.

turn off the water, remove the hot & cold stems on the shower remove and cap the tub spout then blow air thru the shower arm. this will remove ny debri that is in the diverter in the shower valve. Then put everything back and see if that helps.

jadnashua : Way deeper than the aerator stage -- and yes the aerators had deposits but are clean now.

Winslow (followup please)

I rigged up an old PP stem with a fitting so I could attach my air compressor to it.
I then held my hand over the spout (diverter oriented to spout) and "Just" blew out the "cold" side which as previously noted improved the volume and pressure to some degree.
Hot side definitely has normal pressure and volume so didn't blow it Nor the diverter.

QUESTION {as will have to reinstall my compressor setup again}:

Can the diverter be clogged from the cold side and "Not" the hot?
My logic (rightly or wrongly) is once the water gets past the stem and seat from either side (hot or cold) it enters a common cavity where it is routed either up or down.
I woud think the opening to the diverter chamber would be larger than the seat opening {never seen a cutaway of a PP body} and blowing air from the cold side
(had a hard time holding my hand over spout because of air pressure) would indicate it being clear blowing from the cold side.