I agree with the above and possible over fertilization. They look very dark green. Well when flowering begins is when you ween them off the nitrogen so that should clear that up and you might have a little bit of a magnesium deficiency which is common in soiless/soil. The only bad thing is that nutrient supplements with Mag seem to either raise or lower the PH oddly enough. If you can find a neutral one then let me know. Your plant looks nice and that bulb is great.