#leaves

Hello everyone, I've been cultivating this cannabis plant since august/september 2022. Nevertheless, I've noticed the lower pairs of leaves have been dying lately, for no apparent reason. Do someone knows what may be occuring and, if does, how do I remedy it?

4 weeks veg from seed on Friday, soil, using floraflex, temps 75.6 average, rh 73.5%, growing under a single 650w led located 42" away dimmed to 50%. Tap water .01ec, mix cal mag to .3-.4 ec, floralex 2g v1 and v2 per gallon ec ends at 1.6-1.8, i than adjust my ph to 6.5. Fans blowing on the...