OK, short update. I have them under HPS, biggest one is 17 inches, not counting roots. I created a little CO2 generator (2 liter bottle, water, sugar, and yeast) and ran the tube into the basin of the aero. I figure the roots can take in the co2 and the co2 should be pretty well trapped in that compartment. The plants are budding nicely. I kept all 7 alive. The biggest has grown about 10 inches in the last 2 weeks. I'm thinking, total time might be 10 weeks from seed using aero and hps. You could easily cut that down by cloning.
I'm curious to see if the CO2 does anything noticeable. They're growing good now so... I've been doing nutes by eye...but it basically works to splitting weekly feedings in half, giving clean water until the cloudiness disappears and then nutes when clear.
I attached a pic.