I have a 1/2 HP submersible pump with a wellsaver 52 gallon upright diaphragm tank(from Lowes). The pump is 9 years old and the tank is 6 months old, the old one leaked. I have it set at 40/60, 38 for the cut in. My problem is that when we are using water now, it drops from 60 to 40 in less than 10 seconds and then it fills itself back up in less than 10 seconds. So its cutting on every 20 seconds or so. I have read through all of these posts and tried a lot of the things that you all have mentioned. I let air out of the top and no water came out with the air so that was good. I turned the power off and let the water run to zero and checked the pressure on the top of the tank, an it is then at zero and the tank doesnt feel nearly empty. This has been ongoing. One other thing i tried when i emptied it and the pressure was zero was to fill it with air up to 38 and then it didnt short cycle like now. It seemed to gradually get worse over months.

Two side questions...Whats the difference between a diaphragm and a bladder in a tank?

What would be a normal amount of time for the pump to cycle on and off, say if i was watering the yard?

Thanks for your input!