LED diodes are produced in batches sometimes known as ‘bins’. No one batch will be 100% the same as another as by its nature the production process of LED diodes wont be able to replicate the spectral output of one batch to the next . Cree one of the largest and most respected manufacturer of LED diodes quotes an acceptable threshold of +/- 7% between batches. This is very simular to batches of paint or wallpaper where they are manufactured to the same standards but there can be a slight variation that can only be seen when compared.

 

You will find Cree LED’s in most high quality aquarium lights as well as other high end LED products. If one were to buy 2 aquarium lights at the same time one would confidently expect the spectral output of each channel to be pretty similar visually but if one were to purchased lights from different manufacturing periods of say the initial run D8976001XXXX and D8976004XXXX you will have a much higher chance in seeing a difference in output based on the fact that all of the LED’s in both lights will have originated from different Bin’s.

 

However the human eye will not neccesarily render the slight differences correctly due to the way the cones within the eye detect certain colours so the shift can be exaggerated but in testing will have very little to no difference with regards to available photo synthetic radiation levels for the coral.

 

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