I would say Cal mag as well but you upped the dosage and still nothing. That makes me believe you are having a PH "Drift". I have experienced this before in soil mixes that are heavily peat based, supposedly they tend to have PH spikes after watering that lock out Calcium, and Magnesium making it appear deficient, then when you go to remedy it, you often funk with the PH balance even further. Another thing that can do this is a Chlorinated water source (Tap water, some bottled water's...). These have been problems I have encountered with exactly the same symptom's before. Do not convince yourself it is the light, I did myself only to find out it was something I hadn't paid mind to. She will pull through though, might not be the prettiest smoke, but it shall be potent!