ThaiBliss, I know you grow outdoors a lot. But I think you might find this interesting. I have some Z's growing. Before this I did an experiment that I always wanted to try. So I used a 1000 watt HPS for the entire plant, but on one side of the plant I supplemented a 400 watt UV. It was a Fem GT. But the calyxes were bigger on the UV side, and the Thai influence was also more visible. I'm doing the same with my Zamaldelica. It was actually two different high's. The UV I used 6 hours a day on it.
I've always wanted to try supplementing with a strong UV bulb. I grow inside with a combination of 400 watt sodium, and a 400 watt metal halide for significant blue spectrum. I do it in a 3 x 3 foot area which is pretty intense lighting.
What specific 400 watt UV bulb did you use?
Thanks,
ThaiBliss