My preliminary research hasn't turned up much and it doesn't seem like there has been much discussion here on RC about the switching frequency and duty cycle of LED lighting on photosynthesis of zooxanthellae and growth rates of corals.
I am in the process of designing a LED driver circuit and I am trying to figure out optimal on/off times. I want to find a balance between what is ideal for the coral and macro algae and the flicker fusion threshold for humans, fish, and invertebrates like shrimp. I'd imagine something like a mantis shrimp (which really isn't a shrimp, I know) with 12 color receptor cones and 4 color cancellation cones has a higher cone density than humans and would have a higher flicker fusion threshold.
These are the articles that I have come across and seem to address some of the things I am concerned about regarding the frequency and duty cycle regarding photosynthesis.
Red and blue pulse timing control for pulse width modulation light dimming of light emitting diodes for plant cultivation
Effects of Frequency and Duty Ratio on the Growth of Potato Plantlets In-Vitro Using Light-emitting Diodes
Effectiveness of Flashing Light for Increasing Photosynthetic Efficiency of Microalgal Cultures over a Critical Cell Density
Intelligent lighting system for plant growth and development
Comparative performance of light emitting plasma (LEP) and light emitting diode (LED) in ex situ aquaculture of scleractinian corals
From these articles, it seems that a lower switching frequency with a somewhat lower duty cycle would potentially produce a higher photosynthetic efficiency. Granted, the majority of those articles were concerning terrestrial plants.
Frequencies just below the kHz range up to about 5kHz seem to have results similar to constant light, with frequency around .1-1Hz showing results better than a constant source, but this would be rather annoying to say the least.
Has anybody found articles relating the switching frequency and/or duty cycle of LED (or other lighting) to corals?
Have any of you experimented with this yourself?
What is your experience with frequency and duty cycle?
Do most people just run it at 50% duty cycle and call it good?
The second link shows some potential for a lower duty cycle resulting in higher photosynthesis rates than with a constant source, which is appealing to me. I like the idea of being able to further reduce power consumption with positive results for the coral. Possibly have a microprocessor controlled lighting setup that runs a lower frequency that is ideal for photosynthesis while everybody is at work/school and something more appealing the rest of the time.
I'd love to experiment with this, but I lack the room and funds. I would love to get some space in a lab to test some of this out.
I am in the process of designing a LED driver circuit and I am trying to figure out optimal on/off times. I want to find a balance between what is ideal for the coral and macro algae and the flicker fusion threshold for humans, fish, and invertebrates like shrimp. I'd imagine something like a mantis shrimp (which really isn't a shrimp, I know) with 12 color receptor cones and 4 color cancellation cones has a higher cone density than humans and would have a higher flicker fusion threshold.
These are the articles that I have come across and seem to address some of the things I am concerned about regarding the frequency and duty cycle regarding photosynthesis.
Red and blue pulse timing control for pulse width modulation light dimming of light emitting diodes for plant cultivation
Effects of Frequency and Duty Ratio on the Growth of Potato Plantlets In-Vitro Using Light-emitting Diodes
Effectiveness of Flashing Light for Increasing Photosynthetic Efficiency of Microalgal Cultures over a Critical Cell Density
Intelligent lighting system for plant growth and development
Comparative performance of light emitting plasma (LEP) and light emitting diode (LED) in ex situ aquaculture of scleractinian corals
From these articles, it seems that a lower switching frequency with a somewhat lower duty cycle would potentially produce a higher photosynthetic efficiency. Granted, the majority of those articles were concerning terrestrial plants.
Frequencies just below the kHz range up to about 5kHz seem to have results similar to constant light, with frequency around .1-1Hz showing results better than a constant source, but this would be rather annoying to say the least.
Has anybody found articles relating the switching frequency and/or duty cycle of LED (or other lighting) to corals?
Have any of you experimented with this yourself?
What is your experience with frequency and duty cycle?
Do most people just run it at 50% duty cycle and call it good?
The second link shows some potential for a lower duty cycle resulting in higher photosynthesis rates than with a constant source, which is appealing to me. I like the idea of being able to further reduce power consumption with positive results for the coral. Possibly have a microprocessor controlled lighting setup that runs a lower frequency that is ideal for photosynthesis while everybody is at work/school and something more appealing the rest of the time.
I'd love to experiment with this, but I lack the room and funds. I would love to get some space in a lab to test some of this out.
