This is the final result of a trial comparing LEDs and T5s fluorescent lamps in a stacked vertical hydroponic system. The LEDs did as good a job as the T5s but used 1/3 of the energy. Basically, the Dark Red/Blue LED Production Modules peak at 450 nm and 660 nm. Blue diodes are also useful for anthocyanin content. If growing red lettuce varieties, sometimes higher blue light levels may be necessary. Cooler ambient temperatures also increase anthocyanin content.