AHA! found the thread.
http://ecorenovator.org/forum/geothe...html#post34159
The whole thread is pretty relevant to your DX rig in the greenhouse and/or this setup. The majority of the participants in the discussion have put together their own unique flavor of system that would have cost much more if farmed out. The hands-on knowledge and experiences (and opinions) of various members makes for some highly constructive discussions (and arguments). I would not have attempted many of the rigs I have completed (with any level of success) if not for these people. To gain intimate knowledge about any subject, you have to find people who know what they are talking about, and are willing to discuss it. I am SO glad I found this forum, and the people who keep it alive.
The post I originally recalled is here:
http://ecorenovator.org/forum/34159-post15.html
Happy reading!