Judging from your pics, you seem to have a few issues going on. With any half reasonable soil mix, there should be enough nutrients for 4-6 weeks at least. So I would say, too much ferts, too much water and too much calmag. Also another thing I noticed is that there are some old/pulled leaves on the top of the soil in your pots. This can cause fungal diseases to form and judging by the black spots on your leaves, they seem to have that too. So I would say, ease up on the fert, give calmag every 10-14 days, wait until the top 2 inches of soil is dry before watering and make sure to remove any fallen or dead leaves from your grow area, as these are just waiting for fungus to grow on them. Hope this helps.