Here is a solution without draining the tank.
When the pressure is at the minimum setting where the pump starts, and with the power off, add AIR through the Schrader valve until the pressure reaches the shutoff pressure. You will want a compressor for this because it is a lot of pumping with a bicycle pump.
Alternatively; turn off the power and use all of the water in the tank. Then fill it with air to the pump START pressure.
If you put in too much air it will come out through a faucet the next time the pressure drops.
If the air is properly maintained your tank will have the same drawdown capacity as a bladder tank of the same size.
If you have a sight gauge on the tank it is easier to maintain the proper air level.