A few months ago the pressure in my shower was just fine, then one day i turned the water on and it made a funny noise and the pressure was horrible. I messed with the knob a little and after about 1 day it fixed itself and everything was good. I figured something was clogged somewhere. Then it happened again the a few days ago. I got the water pressure a little bit better but its still not where it was or should be. Any ideas on whats going on? The pressure in the sink is normal, its only in the shower. thanks!