Thank you for your lovely post, Cannabox! And yes ... outgassing/phthalate poisoning was in the forefront of my mind for my first grow. This time however I am reusing equipment that was proven in the first grow, with a few exceptions.
The tent is cleared of suspicion imo: it performed well the last time, and has had a hot hot summer in the top of a closet to finish "curing out". It is a Secret Jardin DR120. I was more worried with my rDWC experiment about the 1/2" plastic tubing, since I'd read the online reports that a batch of it (from China, wouldn't you know) was implicated in a rash of indoor grow failures, including Federally legal salad crops.
I am convinced that the problem with the two Gimps is congenital, and it seems to be a sensitivity to light. The shaded undergrowth is actually turning into decent, quite green leaves. I've cut 3x sprigs from the two Healthies and Quasi, but so far my cloning mojo is at zero.
First three pics are the Gimp. In the first, some fairly healthy leaves that have been somewhat shaded.

The second image shows how nasty (she?) looks from the top. This is the plant that has not yet shown sex, while (her) three tentmates showed soon after the first topping.

This pic shows the screwy tops, some nice growth underneath, and scorch marks that I think are left over from my misadventure with the plasma light.
Next is Quasi. Healthy underneath,

and less so from above.

Finally, nine attempts at cloning. I am on day nine. No roots and the leaves are dying. It smelled of hay under the humidity dome. Top and bottom rows are from the Healthies; center is from Quasi. I didn't take Gimp cuttings this time. cn
