Quoted from report of Tim Wijgerde: “Proper lighting is one of the key aspects when maintaining a marine aquarium with corals and reef fishes.
First, light is essential to the growth of reef-building corals. These corals are host to symbiotic dinoflagellates known as zooxanthellae, which use light energy for photosynthesis, a biochemical process in which carbon dioxide (CO2) is converted to organic compounds such as glycerol, carbohydrates, fatty acids and amino acids. These compounds are in part translocated to the tissues of the host coral, which uses these for growth and metabolism (Muscatine et al. 1981; Muscatine 1990;
Furla et al. 2005).
When regarding light for aquaria, three factors are important; light intensity (irradiance), spectral distribution and light distribution.
In terms of spectrum, sufficient blue radiation is required to evoke healthy zooxanthellae and coral growth, and chlorophyll synthesis (Kinzie et al. 1984, 1987; Wang et al. 2008; Wijgerde et al. 2014).
In addition, to properly visualise the colours of all aquarium life, all wavelengths must be present in a given spectrum. This means that the “ideal” light spectrum for the average marine aquarium is continuous, with a blue peak to create a natural effect. This is comparable to a seawater depth of approximately 10 meters, where all colours are still found, but with decreased presence of red and orange. This is due to the fact that seawater selectively attenuates sunlight, with light of longer wavelengths being filtered more effectively (Mass et al. 2010)”.
As well as ensuring these primary spectral requirements, Philips Lighting has opted to improve the spectral content in order to deliver even better color rendering, maximized photosynthetically active radiation for the corals and enhanced phosphorus reflectivity.