Short cycling

[DownTheWell]

I have a 30/50 switch and a 20 gallon pressure tank.
During the last two weeks or so, I noticed slight but frequent drops in water pressure that go away after a couple seconds.
Running water and I see the pressure drop from 50 to 40 relatively slowly and then drop off sharply to 30 and the pump kicks on and pressure goes back to 50.
This is constant, takes maybe a gallon or 2 of running water.
Leaving a faucet running and the pump kicks on almost constantly.
I replaced the pressure switch a year or two ago - the little stem was plugged.
I turned power off to the well, I am pretty sure I drained the tank correctly and checked the pressure on the tank, showed as ~48.
I shook the tank and banged on it and it doesn't seem like water is all the way to the top ~ I did hear sloshing but it didn't seem like a lot, knocking the tank and it sounds like water is about halfway up in the tank.
I am thinking of running up to Home Depot/Lowe's and buying a pressure tank. I called my plumber and I am waiting to hear back.
Does this sound like a pressure tank problem to you?

 

[Reach4]

EDIT:

If you have a 30/50 pressure switch, and it is still set for that, drop the air precharge to 28. Your too-high precharge would explain a stutter in air pressure. Air precharge is always set and checked with water pressure is zero.

There should be no water in the tank when the water pressure is zero. So you may well need a new pressure tank. If you do change tanks, consider upgrading to 32 gallons. That size still has a 1 inch NTP connection.

If that doesn't fix it, include seconds on and off in your description.

 

[Sponsor]

 

[DownTheWell]

Ok, powered the pump off. Drained the tank - little to nothing came out.
Bled air out of the pressure tank until it showed about 28 psi. Ran water from a faucet and I guess it acts normal now.
The rate at which I see pressure drop from 50 to 30 is smooth and slow.
That seems strange to me.
The condensation I see on the tank - it's about 80 out - goes maybe a third of the way up.
I do want to get a larger tank.

 

[Reach4]

Ok, powered the pump off. Drained the tank - little to nothing came out.
Bled air out of the pressure tank until it showed about 28 psi. Ran water from a faucet and I guess it acts normal now.
The rate at which I see pressure drop from 50 to 30 is smooth and slow.
That seems strange to me.
The condensation I see on the tank - it's about 80 out - goes maybe a third of the way up.
I do want to get a larger tank.

That's about right. Humid today! Sounds like success. A 20 gallon tank will provide around 5 gallons of water. Most of the space is captive air.

The way it works is that at 30 the pump kicks on. The tank still holds a bit of water, and delivers that to fill the short gap, as the submersible pump gets up to speed.

How long does pump run at minimum? You would like a minute or more. If you have room, bigger than 32 gallons is good. The only slight extra thing you have to deal with is that the connection is 1-1/4 for bigger tanks. Easy adapter.

 

[Valveman]

Even doubling the size of pressure tank only cuts the cycling in half. Larger tanks are not the way to stop cycling, a Cycle Stop Valve is. You don't need a larger tank as even the 20 gallon is four times larger than really needed with a CSV.