ThanksThis could depend on the quality of the Diodes being used. As mentioned the UV is used to increase Trichome production. The Trichomes act like a sunscreen shading the flowers from getting too much light is my understanding. There is something to be said about this subject.
I'll have to look at that soon thanksThat is for the thc benefit with uvb. The uva in led lamps will not do that. It may help with other processes but not increase in thc.
The uv and far red on a newer light board is meant to be on as part of the spectrum the whole time.
I think they put a switch on budget boards because of the cheap red and uv diodes. Cant think of a plant related reason.
All of the spectrum with the enhanced blue and red diodes has been shown to increase photosynthesis and plant health and the far red proven to increase yield.
Best info on cannabis and grow lighting is from professor Bruce Bugby at the university of utah cannabis lab. Can be found on you tube.
He is also the president of Apogee the makers of professional light meters.
So your saying these board are ment to have the reds in through out all flower or not? Sorry bit lost now, I'm wheb I read that link or video I will under stand this lol