Hi guys,
I wanted to address the question of colored LEDs in lighting. In truth they don't add much with respect to PAR or PUR. In fact our Coral Pro model - designed for frag or grow out tanks has no green or red or yellow. Just white and blue and violet. However - and this is a very important factor - a light that has blue and white LEDs will look very much like a bottle of Windex. Yep. We human see these colors - red and green and yellow - especially green - and they make the tank look more natural to US.
When I am designing a light - a new model - an update on an existing model - or a custom build - it is always a compromise between as much of the right Kelvin white LEDs and Blue and Violet LEDs - all which grow coral - and the red and green and yellow LEDs. The first group grow coral and the second group make the tank look good to the human eye.
I once took one of our first generation blue/white LED lights and took picture of my tank in one specific spot and then put in the model we just replaced it with - that had the three colors mentioned above - and took a picture of the same tank and same spot and compared the pictures - and that picture told the whole story.
The blue/white only looked bleak and unnatural.
The model with a few red and green and yellow looked great.
You need some colored LEDs to make your tank look normal and natural to you.
Hope this helps.
Rick Schott
Founder
Reef Radiance
I love it
In general plant physiology, the term Photosynthetically Active Radiation (PAR) refers to the radiation in the range of wavelengths between 400 nm and 720 nm. This is the energy that is absorbed by the assimilation pigments in blue-green algae, green algae and higher order plants. The wavelengths for the lower limit (400 nm) and an upper limit (720 nm) are not entirely rigid. Photosynthetic reactions have, for example, been established in some algae at wavelengths shorter than 400 nm. In general, the lower limit depends on the structure and the thickness of the leaf as well as on the chlorophyll content. Some research projects have shown 700 nm as the upper wavelength
- 400 nm to 510 nm: strong light absorption by chlorophyll, high morphogenetic effect
- 510 nm to 610 nm: weak light absorption by chlorophyll, no morphogenetic effect
- 610 nm to 720 nm: strong light absorption by chlorophyll, high morphogenetic and ontogenetic effect
This response function can be considered as a mean spectral response function. A number of different investigations have shown that the spectral absorption spectra of various plant types can be very different. These differences can also occur, in a single plant, e.g. in leaves of different ages or with different thicknesses, chlorophyll content, etc.. It should also be noted that the spectral response function for photosynthesis is defined with avoidance of mutual cell shading, experimenting with a young, thin leaf or with a thin layer of algae suspension.
The spectral distribution of the response function for photosynthesis might give the impression that visible radiation in the green range centered around 550 nm contributes very little to the photosynthetic process, and therefore is of minor importance. Just the contrary has been demonstrated by experiment. It is precisely this green radiation that yields the greatest productivity and efficiency in densely populated arrangements of plants or in thick suspensions of micro-organisms. This discovery is important for investigations into the yields of plants in the lower layers of wooded areas or of greenhouse stocks, or in deep water (e.g. in sea plants).
