When the gauge of the filter exceeds 5 lbs of pressure, the normal pressure is around 20, once per week, after vacuuming.
To clean dirt from the sand filter.
a) Stop the pump
b) Put the filter set to "Backwash"
c) Start the pump 2 to 3 minutes depending on the dirt from the pool
d) Stop the pump 30 seconds
e) Put the filter in position "Rinse"
f) Start the pump 30 seconds
g) Stop the pump 30 seconds
h) Put the filter in position "Filter"
i) Start the pump