I have used all 1/2 inch CPVC pipe and fitting on the whole project. The sizes here will make a nice desktop Light Box, you can make it any size you want or need. Just remember you will need 2 pices the same size for the width and 2 of the same size for the depth. The 4 legs will all be the same. I did not use the cleaner on the pipe before I glued it, I just don't plan on running any water thought it so I see no need for it. The glue holds just fine without it.