I know it sounds unbelievable, but you can replace that 220 gallon equivalent tank with a 4.5 gallon size tank.
A 220 equivalent tank only holds about 30 gallons of water. That is still a pretty small tank for a 20 GPM pump and/or an irrigation system that might use 2,000 to 4,000 gallons per day.
Your well is strong and that is where your water comes from. The tank is only there to slow down the cycling on/off of the pump. With a Cycle Stop Valve the cycling is eliminated because the water goes right past the tank at the exact rate it is being used. So you don’t need a very large tank.
You can purchase the entire PK1A Pside-Kick kit with the CSV1A valve, 4.5 gallon tank, 40/60 switch, 75# pressure relief, pressure gauge, and other fittings for much less than the cost of a big replacement tank. Believe it or not your pump will last longer from cycling less, and the pressure will be better, especially when running the irrigation system.
You can purchase one here.
http://cpkits.com/products/pk1a