Also, don't follow the advice of most "growers." Most have done little to no research themselves and rely solely on their experience. The best growers rely on their experience, but also research and try to innovate upon tried and true methods. In my experience forums are not always reliable...
You transplanted them into miracle grow soil. Even the organic soil has times release nutrients in it which are too much for cannabis plants. They quickly become nitrogen toxic followed by other toxicities. Miracle Grow soil is one of the worst brands of soil for cannabis plants. I personally...