I know this is weird but when I went to move some of the sprinklers on my 20-year old system, I discovered that the PVC pipe is bigger than 1/2" and smaller than 3/4". Flummoxed I vaguely remembered the guy who put the system in talking about this 5/8" pipe he had which he felt was better than 1/2" because more water could get through. At the time I knew nothing about sprinkler systems and I said, sure, go ahead. Now what do I do? I really don't have it in me to replace all the piping which is otherwise fine. And at two locations, I can add swing joints to the current 1/2" female threads holding my old Toro 570s. But I was hoping to cap off most of my old heads and switch to four Hunter PGJ rotors which will involve cutting into the pipe at two locations and gluing in threaded tees. Does anybody have any idea how I could do this? Thanks.