Really, just order a board with solid state relays on it and problem solved.
billgates: Do you use a transformer to pug in your 24VAC controller PSU?
Sorry BillGates, not sure what you mean. There is a wall wart giving me 24VAC which is used to drive the solenoids. I then feed this into a rectifier and VDC regulator to give me 9VDC to power the Arduino.