The way photosynthesis works is really quite simple. There are two pigments responsible for absorbing light energy and converting it into photosynthetic energy called Chlorophyll A and B. These pigments absorb light with the highest efficiency (conversion from light energy to photosynthetic energy) at 439nm and 469nm blue, and 642nm and 667nm red. Companies like Hydro Grow who use the 9mm approach fill their grow light with LEDs around 440nm, 470nm, 640nm and 660nm red so they can “hit the bulls eye”, or have the highest conversion rate from watt energy to plant energy. Companies like Advanced LED who use the shotgun approach, fill their light with every color under the sun so that at least some of their wavelengths hit the target – a much less efficient approach.
Now imagine by looking at the images above that the bulls eye represents the 4 wavelengths used most efficiently by Chlorophyll A and B at 100% absorption. Move outside the bulls eye to the next ring and imagine that this area is filled with alternate colors such as 630nm red, 615nm orange, 380nm ultraviolet, or even 415nm blue, wavelengths that Chlorophyll A and B absorb with lesser efficiency (10-50%). Now move to the outer most ring and imagine that these colors, such as 3000K white or 585nm yellow have little to no efficiency for chlorophyll absorption (10% or less). When you begin to think of LED Grow Lights in this way, it is easy to conclude that Advanced LED’s lights produced nearly 3x less yield per watt compared to Hydro Grow because they utilize a poorly designed “shotgun” spectrum.
Companies like Advanced who use the shotgun approach of selling LED Grow Lights with 11, 13 or even 15 wavelengths, are telling the educated consumer they have no idea how to build a proper grow light. Instead they load their light with everything they can in hopes that at least a few of their elements will hit the target, and while their products certainly do grow plants the results are very poor compared to properly developed LED Grow Lights. We believe this is the reason the Advanced Diamond Series light produced nearly 3x less yield per watt compared to the Hydro Grow 336X in the independent grow test shown in our LED Grow Light Review.