Critical purple auto

The leaves on my plants are starting to fold up like a taco, some yellowing.. Not too sure what is going on. My friend suggested that it was a calcium or magnesium deficiency and it matches the description online but I usually give 3 or 4 ml per gallon damn near every time i water, is that enough or too much even? They are 5 weeks from seed today and all 3 are flowing very different and at a different pace..