Europhyllia
Fri, 31st Dec 2010, 12:08 PM
Had so much fun exchanging ideas in Allan's thread that I wanted to start another and get some ideas there.
I also have an ulterior motive to it too. Stephen got me hooked on LEDs. I am loving the light we made for my seahorse tank.
I am considering saving up for an AI LED fixture for the big reef tank. :wub:
The question is whiter or bluer and while reading my way across the internet I came across some really good articles.
Here's the one by Sanjay of course with the focus mainly on PAR:
http://www.advancedaquarist.com/2010/2/aafeature2
So of course I need to know what PAR is and how much I need. Found some great info on this blog:
http://blog.captive-aquatics.com/captive_aquatics/2010/08/par-and-reef-aquarium-lighting-what-is-par.html
PAR is important because it is roughly the measurement of how much usable light energy is available to your corals, anemones, clams - your reef aquarium in general!
...
This greatly depends on the species of coral or other photosynthetic animal, but the acceptable range is roughly 100-450 PAR, measured as PPF (which most PAR meters do). Obviously the low end is preferred by low light corals such as mushroom corals and elegance corals, whereas the high end would be acceptable for shallow water 'SPS' species. For those of you with nature or planted freshwater aquariums, the PAR requirements of plants tend to be lower: between 20-200 PAR, depending on the species.
Of course it's never that simple and so I got to worry about PUR
The wavelength of the light must be considered as well, especially in broad-spectrum bulbs (for instance, 'daylight' bulbs) and in LED lighting (http://blog.captive-aquatics.com/captive_aquatics/led-lighting/). PUR (http://blog.captive-aquatics.com/captive_aquatics/2010/09/pur-and-reef-aquarium-lighting-what-is-pur.html) (photosynthetically usable radiation (http://blog.captive-aquatics.com/captive_aquatics/2010/09/pur-and-reef-aquarium-lighting-what-is-pur.html)) is a measurement that's desirable to have with LED lighting in addition to PAR, and in fact, matters more due to the large amount of photosynthetically unuseable light produced by LEDs.
More on that here:
http://blog.captive-aquatics.com/captive_aquatics/2010/09/pur-and-reef-aquarium-lighting-what-is-pur.html
PUR stands for Photosynthetically Useable Radiation. PUR differs from PAR (http://blog.captive-aquatics.com/captive_aquatics/2010/08/par-and-reef-aquarium-lighting-what-is-par.html) because the basic definition of PAR is any light in a specific frequency range. PUR is the usable portion of PAR, and different photosynthetic species will have a different PUR range to which they respond.
For example: you are given a choice to illuminate your coral with two different lights, each with the same PAR value. However, one of these lights produces energy that peaks at 450nm, or the blue spectrum, and one peaks at 590nm, or the yellow spectrum. For zooxanthellae in your coral's tissue, the light peaking at 450nm will have greater PUR than the light that peaks at 590nm, although the PAR numbers are the same.
I wonder what the PUR range is for plants? Anybody know?
This article almost makes me want to get the 'bluer' LEDs. lol:
http://blog.captive-aquatics.com/captive_aquatics/2010/11/comparing-leds-theyre-not-metal-halides.html
Guess I'll have to look up the spectographs for the bulbs used...
I also have an ulterior motive to it too. Stephen got me hooked on LEDs. I am loving the light we made for my seahorse tank.
I am considering saving up for an AI LED fixture for the big reef tank. :wub:
The question is whiter or bluer and while reading my way across the internet I came across some really good articles.
Here's the one by Sanjay of course with the focus mainly on PAR:
http://www.advancedaquarist.com/2010/2/aafeature2
So of course I need to know what PAR is and how much I need. Found some great info on this blog:
http://blog.captive-aquatics.com/captive_aquatics/2010/08/par-and-reef-aquarium-lighting-what-is-par.html
PAR is important because it is roughly the measurement of how much usable light energy is available to your corals, anemones, clams - your reef aquarium in general!
...
This greatly depends on the species of coral or other photosynthetic animal, but the acceptable range is roughly 100-450 PAR, measured as PPF (which most PAR meters do). Obviously the low end is preferred by low light corals such as mushroom corals and elegance corals, whereas the high end would be acceptable for shallow water 'SPS' species. For those of you with nature or planted freshwater aquariums, the PAR requirements of plants tend to be lower: between 20-200 PAR, depending on the species.
Of course it's never that simple and so I got to worry about PUR
The wavelength of the light must be considered as well, especially in broad-spectrum bulbs (for instance, 'daylight' bulbs) and in LED lighting (http://blog.captive-aquatics.com/captive_aquatics/led-lighting/). PUR (http://blog.captive-aquatics.com/captive_aquatics/2010/09/pur-and-reef-aquarium-lighting-what-is-pur.html) (photosynthetically usable radiation (http://blog.captive-aquatics.com/captive_aquatics/2010/09/pur-and-reef-aquarium-lighting-what-is-pur.html)) is a measurement that's desirable to have with LED lighting in addition to PAR, and in fact, matters more due to the large amount of photosynthetically unuseable light produced by LEDs.
More on that here:
http://blog.captive-aquatics.com/captive_aquatics/2010/09/pur-and-reef-aquarium-lighting-what-is-pur.html
PUR stands for Photosynthetically Useable Radiation. PUR differs from PAR (http://blog.captive-aquatics.com/captive_aquatics/2010/08/par-and-reef-aquarium-lighting-what-is-par.html) because the basic definition of PAR is any light in a specific frequency range. PUR is the usable portion of PAR, and different photosynthetic species will have a different PUR range to which they respond.
For example: you are given a choice to illuminate your coral with two different lights, each with the same PAR value. However, one of these lights produces energy that peaks at 450nm, or the blue spectrum, and one peaks at 590nm, or the yellow spectrum. For zooxanthellae in your coral's tissue, the light peaking at 450nm will have greater PUR than the light that peaks at 590nm, although the PAR numbers are the same.
I wonder what the PUR range is for plants? Anybody know?
This article almost makes me want to get the 'bluer' LEDs. lol:
http://blog.captive-aquatics.com/captive_aquatics/2010/11/comparing-leds-theyre-not-metal-halides.html
Guess I'll have to look up the spectographs for the bulbs used...