So my this person I met is growing a plant, and has commissioned me to figure out the problem. Ocean forest soil, 1/2 strength growbig every other watering, 5 26watt cfl. Has been hot at times, as hes been working on a successful ventilation system. He just started using growbig last week. Also: could this be from splashing some on the leaves? Help! He only has one plant going and doesnt want fungus to overtake his girl! sooo its only on one of the lower leaves so far, but the other lower leaves appear to be developing a similar condition. And Im not sure if this helps, but the leaves above the first row, including the new growth, are starting to look pale around the edges. Thanks everyone!