need a double check

ok so iam like right at the end of 6th week beginning of 7th week and my kids have slowly throught the past 2-3 days i think what is mag. def. i have pics plz look and tell me what u think. temp is 74 they are good on water. ph 6.5 everything is right now except my kids looking like this. but i herd meg. def. right around this time is fine and helps with the buds?? is that right?

Looks fine to me. I dunno wat meg. def. is so idk about that. Great lookin grow tho.

that dont look like a mag def cuz i have that on my clones n that looks nothing like mine something else is going on.. gl

even thoe the ends of the leaves are curling up and turning yellow then dieing and falling off?