Which colors of light are most effective for photosynthesis?

Figure 10.10 Inquiry: Which wavelengths of light are most effective in driving photosynthesis

Which wavelengths of light are the most ..

These same older generation emitters, controller technology & drivers are the reason I did not recommend LEDs of ANY brand for "higher-end" aquarium applications until 2008 (readers of this VERY constantly evolving article in 2007 would note this too).
However NOW we have many reef/planted aquarium capable LED lights and the only thing that separates most are bells & whistles, cost, efficiency of energy input to output, colors one might desire (albeit not necessarily what the photosynthetic life is more efficient utilizing), water proofing/resistance, and warranty. Even in cost, often the other factors will override an initially low cost of many popular LED fixtures.

and leaves to receive the most amount of light ..

Far worse yet would be the cheaper no name emitters used by manufacturers such as BaiSheng, Epistar, & others sold under a plethora of other names for so-called aquarium use. These use daylight emitters that can vary widely in Kelvin Color output from only 2000K to 6500K and are in reality generally much less efficient for photosynthetic aquarium life use other than just plain light!

Think about why a CFL 10,000K daylight is so much different and more expensive than a common household CFL sold in hardware stores, or the many decorative LED aquarium lights or even those for home or flashlight use. Try using one of these to grow your delicate coral or plants (the answer is they will not without use of many). This is the reason most LED aquarium lights were not adequate for supporting life properly until about 2008-9.

Another misunderstanding about LED emitters is targeting the responsive wavelength. While exact coral responsiveness wavelengths are unknown, much is known in a more broad sense (and even more knowledge is growing, such as the "blue band" of coral responsiveness). For example, we do know that much of the yellow and green bands are 30%-80% less efficient for most photosynthetic corals, clams, etc. (although under 24% green light can be useful, but over 25% it is actually detrimental; Reference: )


Start studying PRACTICE TEST CH 10 BIOL 150

Photosynthesis is responsive to certain wave lengths of light energy (see Fig. 7.3, 7.4 & 7.5, Pg. 110-111 in text). The visible spectrum, from Red to Violet light is effective in photosynthesis The most effective colors of light energy are in the Red and Blue/Violet range of the color spectrum. These are the wavelengths of light that are absorbed most strongly by plant pigments, particularly the PRIMARY (and dominant) pigment in photosynthesis, CHLOROPHYLL a.