Yes, and many Growers also grow with synthetic nutrients that are chelated so the plant can up take them nutrients at almost any pH level. You are growing in organic soil so things need to stay in balance. Always go on the lighter side and adjust according to what your plant tells you, not what you think the plant needs. Adding a small dose of a bottled cal-mag product with every feeding and every watering will not hurt you but ensure there is no deficiency of calcium or magnesium when those nutrients will really matter. Again, don't go overboard but stay on the lighter side of a dosage and if your plant needs more it will tell you. Your plants are in no way showing a calcium or magnesium deficiency right now. I would still tend to add a small dose with every food and watering but only somewhere around 1/4 teaspoons per gallon at this point. Your plants are still very small and do not require much if anything at all. Your soil is still absolutely loaded with nutrition all the way around. As your plants get about 10 times the size that they are now, you may want to increase that to a teaspoon per gallon or so.
