We had to buy a nozzle that connected the solenoid valve to the hose. The irrigation drip tubing we bought at home depot attached perfectly to the other end of the valve. You can make your own irrigation tubing by buying some plastic or rubber hose and poking holes into it. Plug the 12V wall wart into the relay box. Make sure you use the socket that is connected to the right arduino ports. For our relay box the top outlet goes to the bottom set of wires and the bottom outlet goes to the top set of wires.