🚀 go-pugleaf

  I've used the solenoid valves out of a washer under computer control.
They run off 110 volts AC, but a bridge rectifier and emitter follower
let me control 'em with a 68HC11 parallel port.

  You'd need to kludge up an adapter to your copper pipe; sounds like a
trip to the hardware store would do it.

  These valves are quite inexpensive; the duplex unit I used was $15.00
new from an appliance repair outlet.