looks like reveg..make sure your dark schedule is totally dark...can also be from nitrogen toxicity looks like they could use a good flush anyways and you have heat stress
Thanks tin, Yea posted something last week about the fan leaves yellowing and got heat stress and nute deficiency only day 6 of adding 3 fans, one exhaust and raising the light 6"... just got second feeding ever of nutes, ff big and tiger bloom right now in week 5 of flower on a super silver haze... just bugged me out cause I've never seen this (even on friends plants) but this is also my first indoor grow... shouldn't be interrupted during dark period as no one is home and it's on a timer, any other possibilities?