the stretch comes more from the red spectrum (so I've read. Blue creates bushier plants and red causes some stretch.), not the 24 hours of light.

They are probably just getting more rest with 6 hours of rest. I think in my reading typically the stomata would close by itself after 20 hours. I wish I could find the link to that article.
daihashi Reviewed by daihashi on . 18/6 vs 24/0 I was wondering if anyone knew what would happen if Swim switched to 24/0 after having some plants at 18/ for 5 weeks. Would this encourage new growth from younger plants but not affect older 5 week plants negatively. This is purely hypothetical I just wondered> Rating: 5