My plant is 1.5 months old, and older leaves are getting yellow and dying, this happens in a pattern, when 3 floors of healthy plants have developed the bottom one starts dying, and so on, as you can see in the picture. I´m not using any ferts, i water (every 4 or 5 days) directly into the soil without watering the leaves. I´m using a 60 watt flourescent light(swirly tubes) 5 inches away from the plant, the plant is well ventilated. It has already lost some 10 or more leaves in total. So, how is she doing? is she gonna make it? Why are the leaves becoming yellow? Thanks four your time!