On Sat, 13 Oct 2012 15:39:25 -0700 (PDT), Nona
wrote:

I would appreciate any insight on whether you feel the failures were due to the piping used, the plumbers' skill or something else related to the system itself.

We are just trying to figure out why these plastic joins keep breaking on us so that when we inevitably need to repair or upgrade
the water treatment system in the future we can do so without fear of flooding and can contemplate finishing off our basement. Thank you!

My money is on the installation. I think you need a better plumber.