dying leafs in lst problem

hi
im running lst on stavia strain, siol, 2 week in to flowering, 135w led. ive already cut the lower leafs up to 1/3 in hight before flowring.
she's very very bushy and after the first trim the leafs closed the gaps in 2 weeks and u cant see the soil trough the top
the broblem is that the leafs under the top start dieing, the ones closest to the siol, they turn very dark green with a brown color in the middel?
thers a good air circulation .i had a heat broblem that been solved.
beside this evry thing is super

thaNks for the reply

Sounds like P. They use it heavily in bloom. Shaded leaves die off in bloom.

looks perfectly healthy. shaded leaves get consumed for nutrients

View attachment 2165716i think they look great, dont over think it bro. Plant leaves have a life cycle, they will brown and fall of at some point. I focus on the top half my plants and That usually tells me if there is a problem. here is my current grow at day 16 of 12/12View attachment 2165714View attachment 2165715