Mephistos AVTx3BOG, first auto run

Weeks went fairly well, leaf tips were getting quite dark green, being my 2nd grow im unsure the exact problem, could be too much nitrogen, which I find unlikely so I assumed its a mag deficiency. There's some mag in my biogrow and none in the root juice so I switched it up. Gonna slowly increase the amount and maybe add some calmag. I can almost see a pistol or 2 on my other 2 autos, so I think next week could be preflower for these guys!