Just as I scared away everyone last month with cabinetry details, in this installment I hope to alienate all but the most dedicated lighting gear-heads. Each form of lighting has several factors to consider, summarized below. The unit for this is Lumens.
Plants require a certain amount of lumens to grow.
Higher efficiency bulbs are going to cost you less to operate, and may offset the initial purchase cost after a few years. This can be complicated to explain, but I'll try to keep it simple. The CRI refers to how close the spectral curve of the light approximates that of the sun, with 100 being the closest. A higher temperature means that the curve is shifted blue, and a lower temperature means the curve is shifted red. Midday sun has a temperature of 5700 Kelvin, so most plantkeepers try to get lights of similar color temperature.