Well, I just dry weighed this lot, and I mean proper dry.
15 oz give or take a few gms. Much better, and 3 of the 6 plants were dead or as good as.
New 4 plants (from seeds) are in the RDWC system now. Let's see what happens....
(had my 1st rdwc issue almost immediately - a small clay pebble made it's way into the system and blocked the Tee reducer at the end of the system. I drained and now installed two mini mesh pots, one over each pipe exit where it leaves the last two pots to be recirculated).