[tewitt1949]

What I did and it works great, is I also have 6 in pvc, I drilled 4 in holes every 10 ft (or what ever you want) in the 6 in pipe. Then I cut a piece of 6 in pvc about 6 inches long. Then cut it long way. Then you can spred it and push it over the 6 inch. It will slide along the 6 inch and you can use it as a door to cover the 4 in hole. They stay put and don't leak at all. If you get a clog, just slide the outer 6 inch piece to get access to the 4 inch clean out hole.

I use a old piece of garden hose to push down the pipe (with vacume on) to break loose any clogs.

These 4 inch holes and covers (6in pieces of pvc) can be added after the system is built.