Our work on the importance of far-red light for efficient photochemistry will soon be published in the Journal of Plant Physiology. PhD student Shuyang Zhen, who headed up the project, found that plants use red and blue or warm white light more efficiently when far-red light is added. Red and blue or warm white light excite photosystem II more efficiently than photosystem I, leading to an imbalance between the two photosystems. Far-red light stimulates photosystem I more efficiently than photosystem II and adding far-red to red and blue or warm white LED light can restore the excitation balance between the two photosystems. This increases the overall efficiency of the light reactions of photosynthesis and also increase CO2 fixation. These findings have important implications for the design of LED grow lights, especially when they are used as sole source lighting. You can find the preprint (and soon the published paper at: https://sitedx.doi.org/10.1016/j.jplph.2016.12.004.