I just now saw this thread for the first time :wtf: ... my NL99 were light-to-medium feeders ... I fed medium ferts, got just the tiniest tip burn, like I like it ... your lower leaves will yellow and drop as you get further into flowering ... that's normal, as I'm sure you know ... I grew mine in soil, and never had to add Cal-Mag+, etc. ... I'm suspecting you MAY be keeping your soil too damp ... let the soil dry out between waterings, and poke a pencil, etc. up through the bottom of your pot, make sure the soil didn't compact, and restrict drainage ... that's first place I'd look ... good luck :jointsmile: