I need calcium?

My babies seem to be suffering from calcium deficiencies. Possibly MG as well. Any recommendations to resolve this? I've got some clawing downward but i think that might be associated.

Worthless without pics

this is one of the leaves from the lower leaves they felt...crispy like heat burn but this wasn't a problem since the new growth was fine.

there is a nut mix you can buy called calmag works great