The LED lights over our reef tanks are completely customizable - but how should we set them up to keep our corals healthy and colorful? Is what looks good best for the coral? Let's break it down and look at the specific colors your coral can actually make use of, so that you can be sure to give your coral plenty of those wavelengths. Acropora and other SPS corals have Symbiodinium species growing in their tissue, and these dinoflagellates have chlorophyll just like a plant... and that chlorophyll can only use certain wavelengths of light - so why not give it to them?
LEDs give off very small ranges of wavelengths - that's why a red LED looks red and not white to us. Our trusty old metal halide bulbs were different - they contained a mix of phosphors inside them which gave off large ranges of light colors. To get the same effect companies like Ecotech Marine, ATI, Aqua Illumination, Kessil, Orphek... etc etc... mix a large number of different color LEDS into their panels. Then, we have to worry about how those LEDs will mix, after all you do need those red LEDs, but you don't actually want to see a red spot in your tank under the light. Different companies do this differently, but most do a pretty good job and it's not something we have to worry about as coral reef tank hobbyists. Our Acropora and other corals seem to do just fine!
Thomas A. Schlacher, Jane Stark, Andreas B.P. Fischer,
Evaluation of artificial light regimes and substrate types for aquaria propagation of the staghorn coral Acropora solitaryensis,
Aquaculture, Volume 269, Issues 1-4, 2007,Pages 278-289,ISSN 0044-8486,
doi.org/10.1016/j.aquaculture....
Abstract: Stony corals are in high demand in the ornamental aquarium industry, underpinning a substantial global trade. Because coral propagation generally has limited success, the bulk of corals is sourced from wild populations, impacting natural coral reefs. Many stony corals contain symbiotic algae and light is therefore a critical factor. Inadequate light (e.g. intensity, spectral composition) may thus be a main reason for death of stony corals in aquaria. The effects of artificial light sources on corals remain, however, poorly documented. Thus, the chief objective of this study was to determine survival and growth of the staghorn coral Acropora solitaryensis under four metal halide lamps with different Kelvin ratings (5000 K, 10000 K, 14000 K, 20000 K). Additionally, the effects of two substrate types (marble or cement) were tested over 85 days. Corals survived better under lamps of higher Kelvin ratings (≥14000 K), but survival was not affected by substrate type. Similarly, coral growth was significantly faster in light treatments with lamps of high Kelvin ratings, and marginally better on cement blocks. Overall, of the treatments examined in this study, the combination of a 20000 Kelvin light source with fragments grafted onto cement blocks produced the best survival and growth of the staghorn coral A. solitaryensis in aquaria. This study demonstrates that culture regimes can be identified to improve coral propagation, but these are likely to be species-specific and dependent on the types of lamps used. Because of the high popularity of corals as ornamental aquarium species, the aquaculture industry has the potential to make a valuable contribution to the sustainable use of marine resources by developing appropriate culture techniques for stony corals that reduce wild harvests and their negative environmental impacts on coral reefs.
Don't forget to like and subscribe if you enjoyed this video!
I upload at least one video each week, so check out my channel for more!
kzfaq.info?sub...