[mdwright]

Here is my well pump system (everything is 8 year old, with no previous problems): Submersible pump, water comes into house through shut-off valve, then pressure gauge and switch assembly (40-60psi), then to sediment filter, then "T's" one side going to 80 gallon pressure tank, and the other side goes to water softener then to chlorination pump and retention tank, finally to carbon filter to house.
I would have to change the initial sediment filter every month, so I decided to get a self cleaning, backwashing sediment filter. I removed the old cartridge style filter and put the backwashing filter in its place. That is when trouble began.
The first time to tried to turn system on, pump short cycles. I thought that the new filters pressure differential was too high for my system (pressure would rise too fast which kicks pump off, a second later the pressure would drop enough to kick pump on, and so on), so I took the new filter out and replaced with a new cartridge style filter. Pump still short cycles when in the filter position. If I 'bypass' the sediment filter, all works somewhat OK, pump kicks on, builds to around 64psi, then shuts off, however the pressure instantly drops to around 45psi. With original sediment filter, pump would shut off at 64, then drop and hold at 60.
I have verified the pressure tank is set at 38psi with water drained.

Any ideas? Please help.
Thank you,
Michael