Athosanswered grow question 5 years ago Unless your base nutrient have a good % of calcium and / or magnesium, then you should always start with a dose of cal mag; enough so your base water is at 0.5 EC (250 PPM) before adding the rest of the nutes. The problem with calcium deficiency is that the symptoms shows weeks after the deficiency starts, so by the time you notice it, it's kind of late.