LEDs, discussion.
- Thread starter Wicked Color
- Start date
I am doing the same as far as more colors. We can discuss our results. Very interested in that. Those graphs and charts do not have anything to do with the fact that Apogee says PAR values maybe as much as 50% off on Blue LEDs. Those are MH comparisons and a lighting chart that was probably tested and perfect with something not LED. IF there was an accurate conversion for Blue LED the Apogee would not discuss a sensor for LED light. LED is just so different from T5 and MH. Not everyone agrees that a photon is a photon is a photon. Corals have to adjust to the different lights we put them under. Ultimately my theory is: The reason we have so many problems with LED with certain coral (that has nothing to do with pests, water quality) is we are either missing something i.e. radiation? spectrum? spread? OR we do not have accurate par numbers with these Bluer LED fixtures we are buying and building. IME too much light=corals slowly becoming lighter and maybe bleaching. That seems to be the major compliant: "My corals were great at first but they slowly got lighter and some even bleached". Same thing happened to me until I moved my coral far away from the LEDs and Im reading low PAR where the coral are happy and growing. My theory again: Two things 1. More light than we think
2. Too many holes in the overall spectrum of the light fixture
I don't feel proven wrong on either of these but again these are my theories based on experience.
2. Too many holes in the overall spectrum of the light fixture
I don't feel proven wrong on either of these but again these are my theories based on experience.
The very first graph is from Apogee, and directly states exactly how much their meter under estimates blue. The issue with the Apogee sensor has nothing to do with LED vs MH, it has to do with wavelengths. The apogee sesnor is calculating the amount of photons hitting the sensor per second. It has no idea what generated the photon, and it doesn't care. Apogee has never said that blue leds are off. They have stated their sensor's measurement of the blue wavelength is off. And the graph shows it (there sensor is the blue line).
I am not sure what you mean by not everyone agrees that all photons are the same. This is a basic principle of physics.
I am not tyring to debate the success or failure of using LED's on reef aquarium's. I am merely trying to explain how a PAR meter works and clarify some misunderstanding of the readings.
I am not sure what you mean by not everyone agrees that all photons are the same. This is a basic principle of physics.
I am not tyring to debate the success or failure of using LED's on reef aquarium's. I am merely trying to explain how a PAR meter works and clarify some misunderstanding of the readings.
I've heard that PAR meters aren't all that accurate in certain areas of the visible spectrum. The comment about misreading blues may be due to another factor. I've read several sources that say blue light can get up to twice the photosynthetic response compared to other wavelengths. Look at the chart here to shed light (no pun intended) on the idea. I'm not implying that blue lights should replace white. All wavelengths are useful for various reasons.
