I have what i believe is a shallow well set up.Can't find wellhead yet System is ten to twelve years old has 3/4" poly feed to 3/4"cpvc inlet to1/2 hp gould jet pump 20/40 pressure switch/30 gallon tank.the pump cycles on after about 3-5 minute run time on faucet.runs about 1 minute then satisfies pressure settings.Want to replace system with new pump and tank,also will be adding areation tank to remove smell and iron.need recommondations on size of pump/pressure switch and tank size.