My only suggestion to add to the other solid advice here is that you may want to take a chunk of your soil out of the plant pot, add some water to it, let it sit for a little while (I dunno, an hour?) and then test the ppms and ph. You will want your rinse water and your first week in reservoir to not be too far off from what the soil measured out. This may sound like work, but it will provide a little less shock to your existing root mass.
By the way, I would love to see your trial - can you post pics of your process and update with your success or (and I don't wish it upon you) failure? I think folks would like to see your experiment because I don't know many folks who routinely switch from soil to dro' with a plant that size.
Good luck, and peace.