I have well water and my bathroom plumbing is of 1990. I just back washed my shower head and it helped my water pressure momentarily. Sediment is a problem, some came out. (I am unable to back wash my faucets because they are in the wall and do not extend into the bathtub). A plumber repaired this problem before by cutting and soidering the mixer to clean it out. I do not want to call him back. Is there an alternative repair for an ongoing problem?