I am putting electrical service to a outdoor shed and a chicken coop. I had outside service to a pool. The pool is no longer there. the wire to the pool was 12/2. I have wired the coop with 14/2 outside wire and I just dug a 18 foot ditch min of 18" deep. I was going to put the wires through the conduit, and I saw the wire coming from the house was 12/2. there is no way I can change that wire at the circuit box. can I use the 14/2 or do I need to change the shed and coop to 12/2?