just hit 3rd week in flowering and have been fighting Cal-Mag issues but today I checked on the girls and some of the low leaves have black on the tips and edges of the leaf? And some looked like they were dying. I know I over crowded my space lol but first grow. Is this normal? Is the plant using all energy up top? Or do I have a serious problem? And yes I'm moving my light up again lol. Thank you all in advance.