My shallow well 1/2hp jet pump is bad so I have a new Sta-Rite 1hp pump not yet installed. There is a CSV1A in the system and running at 40/60. I have had a 20 gallon tank but got to thinking that I would get a smaller tank also so bought a new 4.5 gallon tank. The well serves two small houses. I am now thinking that I should have got a larger tank say 8-10 gallons because of the bigger pump. I think I understand that it will work either way but I read somewhere that higher hp pumps want to run longer.