What kind of excess/deficiency is that?

I don't understand why everyone in the US is so obsessed with cal/mag? It is only needed in slightly higher quantities during flowering. Any decent "grow" nutrient will have more than enough cal/mag in it to be adequate for all stages of vegetative growth. Your leaves are showing signs of being burnt by too much fertilizer, also maybe burning caused by getting the leaves wet while the light was still on. These plants are still very young and the nutrient requirements, plus what is in the "soil" already, means very little fertilizer is needed at the moment. I would only be giving them, at this size, perhaps one dose of quarter strength fertilizer once a week. Once they have become truly established with branches and a height of 14-18 inches, only then would I consider feeding more often. I have found it is better to give weaker feedings of nutrients more often, rather than strong doses all at once. By this I mean, rather than give a weeks worth of feeding in one go, give your plants four feedings of quarter strength, over 10-14 days, depending on size and soil conditions/health. This way there is much less chance of overfeeding and burning the leaves or making the soil toxic. You wouldn't give a toddler a T-Bone steak and it is much the same with young plants, gentle feeding often and not feasts all at once. Hope this helps.... Organoman.