It might be reacting to something poisoning its media or water. What water are you using? I would use distilled water and apply the water from overhead to drain and leach out anything that might have gotten in there.

Thanks for the reply. I'm using distilled water on both of my plants. I thought it was kind of odd that, with both plants in the same spot and same conditions, the other plant is doing fine. I'll go ahead and try watering it from the top and see what happens.

Look out for pests on the leaves and keep the leaves back from whatever heat is dissipating from the CFL. Those compacts are hotter than the tubes and can burn plants if they are too close. I tend to rely on 40 watt tubes since they give better coverage over a larger area... great for a shelf unit in an entire window or two. My VFT likes the 12000 lumens and the south window light it gets.

Be cautious of the water... some water you buy might have minerals added without labelling it so.. Drinking water is a no-no as it is not true distilled water. Make sure the distillation process does not use salt or add minerals and it should be fine. Check the water with a fish tank Ph kit. You can get a color coded easy use kit with little sticks of chemical reactants in a botle at pet stores and just dip the stick in your water source to find out what the water Ph, hardness, nitrites, nitrates, and so forth are. So long as the water is neutral and devoid of most of the minerals and fertilizers, it should be fine after being passed through the pot mixture the plants are in... it will be acidic once it reaches the tray.