Possibly you are in need of new sand or you can go to the pool shop and ask if they have a chemical sand cleaner.
when the pressure is high on filter mode it usually means that a backwash is required.
My Hayward sand filter doesn't have a liner. I just add the sand to the pressure vessel.
This is what your filter gauge will read when it is first start with a new and clean filter cartridge / D.E. or sand.
Probably because it is clean, leave it on the filter setting for a while and you will find that the pressure will increase as the filter gets dirtier, when it get high (usually in the red ) you will have to backwash.
Depends upon your starting pressure and pump type. Generally however you want to keep your max pressure at about 8-10 psi above your first time running the filter or your most recent sand change, if it goes above this run a backwash and a rinse cycle if it still persists at a higher pressure it's time to replace your sand.
Because When the filter is on the water is being pushed through the sand, this brings about a buildup of water pressure in front of the filter and a reduction of water able to get through to the returns. If the filter gets dirty the pressure gets even higher. When the system is set on recirculate the water bypasses the filter so there is no pressure in front of it and as a result of this it is able to move through the system more easily.
Depending on the type of filter it needs to be cleaned or backwashed. Cartridge filter: Hose off. If pressure does not go down buy new cartridges Sand filter: Backwash, if pressure does not go down replace sand DE filter: Backwash, if pressure does not go down remove element from tank and hose off and or acid wash. Also... always make sure you gauge is working
You may need a new pressure gauge. They are inexpensive and can be found at any place that sells pool products. OR That may be all that you are going to get out of the system you have.
What is a normal operating pressure for a jacuzzi sand filter for an above ground pool?"
One way would be that the water never really gets crystal clear. A good rule of thumb is change sand every 5 years. Of course use the correct grade of sand and use the filter manufacturers recommendations for the correct amount. Ken
Depending on the amount of this , you may need a sand trap on the pump, or at least a sediment filter before the pressure tank.
Water is meeting more resistance as it is making its way through the filter media usually indicating that the filter needs to be cleaned. Some times in the case of sand filters it indicate that the sand needs to be replaced.