Jackhazeanswered grow question 6 years ago hi man, sorry i don't know why your plants are taking so long, might be a problem of missing nutrients? are u using pk 13/14, these seems the right moment to use it.
And about your lamp switch...well i'm not very expert about growing, but i am about lights, and without taking to long, change the type of light in this stage of her life is a very bad idea, very stressful and useless at this point.
this might be why your plants are getting forever to fatting up!
Good luck buddy!