Middle of bottom Nolds brown

Can any1 tell me y my bubba kush plant bottom Nolds r turning brown their 2 1/2 weeks into 16/8 light using dyna gro BLOOM only rite now, my og plant doesn't have problem an their same age??? Any advice

Maybe they are not getting enough light, but they are fine if the brown further then there is a problem. Could also be too hot..

Cause top nolds are nice an green I'm using 4 t5 which 2 red spectrum for budding and 2 cool blue lights other plant is not having this problem but one is hybrid which is 2 feet taller than my bubba

Pictures or there is no way to help. Not enough info given. My best bet is either you are overwatering or overfertilizing or else the bottom 1/3 of the plant is not getting enough light therefore it is dying off just like pine trees do in a forest in nature.
And why are you using Bloom fertilizer during the Vegetative stage ???

if it's brown it's dead

hope this helps