When looking for answers to common questions I usually first search the forum that will likely have posts on that topic. I look to the site menu, or menu bar or tab, and pick one from the drop down list.
1. Look into the various fora on this site, found via the Foum Menu, and you will find one that is focused on Plumbing
issues. Others are on Electronic, Engines, Navigation
here is a link to the Plumbing
forum (some may call it a subforum).
2. See any of the many threads linked in this list about Composting Heads.
Hope that helps. Good luck on your decision.