help please my plants are dying

hey evryone i have 2 plants that about a month old.















i only gave them ones a biobizz root juice and after that the problem have started it started from the bottom and then rising above.
and the grow was slown.

it started with sort of spots and curling then become yellowish and now the leaves are burn and can crack.


anyone know what it might be?
and what should i do with the damage leaves? do i need to cut them right now?


thanks for the help!!

That color looks like overwatering to me. Water less often, and start adding perlite to your soil mix, even though it has some in it.

looks like the begging stage of mildew started and than you fixed the problem and the leaf tip suffered or like punk said your over watering

thanks for the help ive stop watering them i hope thell make it..
i have some grey little stuff in the new set of leaves in one of them is it mold? what can i do about it?

should i cut the dried leaves?