Let me preface this by saying that I am not at all a gardener. If anyone is kind enough to answer this request for help, please dumb it down for me. ;-)

I am using a Prepara Pro hydroponic system with a grow light that is on a timer (15 hours on and 9 hours off). I am growing three varieties of basil-- Lemon, Genovese, and Purple Ruffles. The lemon is taking off and growing maybe 2-3 times as fast as the Genovese, which is growing maybe 2-3 times faster than the purple ruffles.

The first and most obvious problem is the brown spots on the lemon basil. The leaves sprout, look healthy (and the plants are growing), but then these brown spots appear. The spots get worse, the leaves droop, and they look like they will eventually fall.

The leaves on the lemon basil were initially flat, but the newer leaves coming in are curled to the back, which made me realize that perhaps the shape of the leaves on the smaller plants are indicative of further problems (you can see those in the picture as well).

I realize that maybe these plants probably have different nutrient needs, but I figured that what came with the system was general enough to keep it all covered. The solution that I am working with is "Power Plant" diluted at 0.1% (the label says that it is 7% total nitrogen, 9% P2O5, 5% K2O, 0.1% iron, 0.05% Mn, and 0.05% Zn, if that helps).

Thanks for any help at all!!

Rick