Autoflower leaves turning brown/purple

temps under 68F at night? They look like thay have a long way to go so don't chalk this up to 'senescence.' The canopy is dying too soon. If a nute schedule has these results, fuck that schedule, lol.

I see very dry soil, get good runoff mate. Personally i had real issues with biobizz nutes and autoflowers, i feel like their dosage recommendations are way too high, i changed to plagon and im breaking records now without any dead leaf throu whole grow.

www.youtube.com/watch think you have it

Looks like your light hanging in the middle and bit to low. The coloring looks like a circle to me everything outside or higher looks good. Put your light a bit higher id say. Do you water till runoff and measure the runoff pH? You should start at a certain height to water till runoff, they look like they can take it now. Also If you feed them 6.2 you probably have a pH 5-6 in your soil, which is too low. So controll runoff pH, put the light higher and try to feed them 75% of the feeding shedule.