Lighting Deep Tanks

Problem: Without realizing how much light aquarium plants need I had a
34"x30"x14" aquarium made to fit into a wall recess. I've been reading
that most freshwater tropical fish prefer lower light levels that
exist in most natural streams. Anyway I've bought two 25w fluorescent
tubes since this was the highest wattage at 30" long. I also got two
reflectors which the manufacturer says increases light by 100% giving
a possible 100w. I guess I need more light but how much would you guys
suggest. I don't want to stress the fish with too much but also want
tall plants for the 30" high tank.