My house which is 40 years old has 1/2" copper lines for the water
feeds. I have a submersed well pump and a bladder tank who's pressure
guage reads 30psi. I also have an exchange filter and a cartridge
filter in line and I've tested with both of them bypassed with
negligible differences. My pump was replaced 10 years ago and the
pressure tank sooner. The pump seems to cycle normally as it has in
the past. I've also checked the air pressure in the tank and it is at
spec.

My measured flow at several faucets is now at 1.6 GPM and I have
noticed a reduced pressure/rate over the past year.

So, my questions to those who know - what/where can I look or do to
diagnose and/or improve this situation? I am reluctant to bring in
a contractor at this point because of economic reasons. What might
my options be?

Thanks all.