That shower head filter can be left out--there may also be a flow restrictor--kind of a washer with a tiny hole---that is some times drilled out to allow for better flow--(It's illegal to do that so don't let the shower police into your home)
New members: Adding your location to your profile helps in many ways.--M--
I didnt see a flow restrictor. Just the filter and the aerator. I am about to hop in the shower and see if the pressure is in deed fixed. I'm glad it wasn't my pump or well that was the issue! Their seems to always be some big unexpected bill every month lately.