View Full Version : Photosynthesis and the Reef Aquarium Part I: Carbon Sources

10-09-2006, 02:08 PM
Photosynthesis and the Reef Aquarium Part I: Carbon Sources

10-11-2006, 09:11 AM
Photosynthesis of Algae in Continuous Light vs. Light/Dark Cycles


Interestingly, three marine microalgae, Skeletonema costatum, Phaeocystis globosa and Emiliania huxleyi,24 were studied for their rates of photosynthesis and carbon uptake mechanisms in continuous light vs. those same species in light/dark cycles (12 h on/12 h off and 16 h on/8 h off). The rates of photosynthesis were nearly twice as high with light/dark cycles as with continuous lighting. In two of the species (S. costatum and E. huxleyi), but not the third, the contribution of bicarbonate to the total carbon uptake increased dramatically in light/dark cycles compared to continuous light.

How this result might relate to growth and nutrient uptake in lit refugia where macroalgae are often grown to export nutrients is not known. However, it is a sign that perhaps continuous light is not optimal, in addition to being more expensive.

Very interesting indeed, it would seem like having some kind of reverse photo period would work best.