Bump- just finishing up my first run of "3000k only". Using an HLG qb288. In veg, was it running it at ~70watts from the wall 2ft over head. Slowly bumped up the wattage, week by week, and have been running at ~159 watts from the wall, driver included. So I'm guessing about 145watts to the actual light?
Anyway, yah, height was controlled very, very well. Every time I started to see some stretch, I bumped up the wattage on the light & it stopped in its tracks every time. Running GDP, GSC & an unknown indica in a 32" X 32" tent. Canopy is a 26" X 32" rectangle, each plant at least as wide as it is tall. Fantastic lateral growth. Responded perfect to pruning- no noticeable wilting, sad leaves or growth slow-down. Temps strayed up into the low 80's near end of august, w/outside temps reaching triple digits. In flower, the tent stays 72-78 during the day, 68-73 at night. Stretch during flower has been modest - but production is excellent, with colas everywhere, stacked a good 8" deep, with extremely short internodal space. Buds are quickly swelling out laterally, just entered flowering week 6 of 8. Closeup pic was taken this morning, the canopy shot is from ~2weeks ago. The girls in back are sativas and will run a good month longer than their shorter cousins