Why all the AI's for sale?

[tripsandfalls]

Full spectrum is basically entirely for coloration.

Advanced aquarist has a good review on fluorescence, and fluorescent pigments in corals. This has been thoroughly discussed in scientific literature (and continues to be discussed). (http://www.advancedaquarist.com/2006/9/aafeature) If you guys take a look at figure 2, it highlights the broad spectrum of wavelengths (both visible and UV) that fluorescent pigments in coral cover--the more of them we hit with our light's emission, the more vibrant our corals look.

In terms of growth, there are photosynthetic pigments that absorb into the visible as well (and even approaching the near IR... or well into the red), but the most common ones (the chlorophylls) absorb around the wavelengths that 'blue' and 'white' LEDs emit. http://reefbuilders.com/2010/08/23/c...nfrared-light/

The reason people switch back to T5 and MH light sources is because these lamps are broadband emission sources, so you're hitting both the growth wavelengths and the other visible wavelengths all with one lamp, resulting in growth AND pretty colors. LEDs are narrow band emitters (ie: they just hit specific bands), so including different colors of LED
helps with color rendition. LEDs have other advantages; smaller fixtures, run cooler, use less power, long bulb lifetime, etc.

As a guy who works on LEDs on the molecular level, I'm stoked about the technology. Sure there's room to grow, but people hanging onto MH and T5 systems may be a little afraid of change.

[Goatman]

Originally Posted by tripsandfalls

Full spectrum is basically entirely for coloration.

Advanced aquarist has a good review on fluorescence, and fluorescent pigments in corals. This has been thoroughly discussed in scientific literature (and continues to be discussed). (http://www.advancedaquarist.com/2006/9/aafeature) If you guys take a look at figure 2, it highlights the broad spectrum of wavelengths (both visible and UV) that fluorescent pigments in coral cover--the more of them we hit with our light's emission, the more vibrant our corals look.

In terms of growth, there are photosynthetic pigments that absorb into the visible as well (and even approaching the near IR... or well into the red), but the most common ones (the chlorophylls) absorb around the wavelengths that 'blue' and 'white' LEDs emit. http://reefbuilders.com/2010/08/23/c...nfrared-light/

Excellent, will have to do some more reading.

Originally Posted by tripsandfalls

The reason people switch back to T5 and MH light sources is because these lamps are broadband emission sources, so you're hitting both the growth wavelengths and the other visible wavelengths all with one lamp, resulting in growth AND pretty colors. LEDs are narrow band emitters (ie: they just hit specific bands), so including different colors of LED
helps with color rendition. LEDs have other advantages; smaller fixtures, run cooler, use less power, long bulb lifetime, etc.

All worthwhile advantages, as long as it is not at the expense of the corals.

Energy saved seems moot when every six months people seem to be upgrading

Originally Posted by tripsandfalls

As a guy who works on LEDs on the molecular level, I'm stoked about the technology. Sure there's room to grow, but people hanging onto MH and T5 systems may be a little afraid of change.

Wary of change maybe but not Scared. I prefer ...so far at least ... the look of MH over that of LED. Again its a trusted method and I have no problem saying it could be because I am used to MH. but I didn't switch to T5 over MH either. The look is not the same. LED is nice but again I don't think its there yet. Again, in Marine Aquaria the "next" thing is always pressed as more advantageous...it makes money.

Again...I'm going to try LED again and see....especially if it warrants it after reading.


But again, people are replacing their fixtures because itr is the newest thing, the newest thing is always pushed and "improved" periodically. Again, I am not as current with LED as you probably are, but It's not a mature tech yet....so again the developments will come rapid for the next little bit i would think.


I must say i like the Aesthetics above the tank with the LED pendants...its the inside i worry about. I have Orphek Pendants and Kessil a350's the adjustable ones....having them hanging down over my rimless tank would look awesome...if they make the livestock look good then I'll not hesitate in switching.

[Jakegr]

Originally Posted by tripsandfalls

In terms of growth, there are photosynthetic pigments that absorb into the visible as well (and even approaching the near IR... or well into the red), but the most common ones (the chlorophylls) absorb around the wavelengths that 'blue' and 'white' LEDs emit. http://reefbuilders.com/2010/08/23/c...nfrared-light/

Just a slight correction. Chlorophylls a and b absorb best at about 475 and 680 nm. They utilize energy from 680 nm photons more efficiently than at 475 nm as the former have an energy content closely matching the ideal level of chlorophyll excitation. In terms of growth, we are primarily concerned with chlorophylls a and b. The more colourful pigments (carotenoids) serve more of a photoprotective role and do not have a major impact on growth, at least in algae.

White LEDs as I'm sure you know are a mix of wavelengths. So you can't say a pigment absorbs best at the wavelengths white LEDs emit, since they emit a very broad spectrum.

[mark]

so I'm getting nothing specifically wrong with the AI Sols, other than maybe aesthetics re:SPS

[subman]

No nothing at all wrong with them. Growth is great and color is good.

Unfortunately it seems lately any thread started with leds in the title attracts all the people with no experience with them to feel the need to tell everyone what's wrong with all LEDs.

[Madreefer]

Originally Posted by subman

No nothing at all wrong with them. Growth is great and color is good.

Unfortunately it seems lately any thread started with leds in the title attracts all the people with no experience with them to feel the need to tell everyone what's wrong with all LEDs.

Haha my thoughts exactly. Well put. I like my Sols. Big learning curve and would buy them again.

[Aquattro]

Originally Posted by Madreefer

Haha my thoughts exactly. Well put. I like my Sols. Big learning curve and would buy them again.

Agreed. While I tend to go on about missing my MH, these are great alternatives and I would buy them again.

[Pan]

Originally Posted by Aquattro

Agreed. While I tend to go on about missing my MH, these are great alternatives and I would buy them again.

I'm coming around.....seems the shimmer is there with my pendants.... but hanging them over coke cans in a cardboard tank takes away from the experience.

anyone locally have pics of kessil a350 (its the adjustble one...tuna i think) and orpkek dif-100 (growing on me more and more....but i'd need three i think....well maybe two and the kessil....maybe a smaller one. Will allow me to do the spotlighting effect i want....Heard back from my japanese friend i'd need a lot of money to get the MH spotlights i was hoping for....

[Aquattro]

Originally Posted by mark

so I'm getting nothing specifically wrong with the AI Sols, other than maybe aesthetics re:SPS

No, not even that. They're fine. If you stood in front of my tank, you'd agree they do a decent job with SPS.

[tripsandfalls]

Originally Posted by Jakegr

Just a slight correction. Chlorophylls a and b absorb best at about 475 and 680 nm. They utilize energy from 680 nm photons more efficiently than at 475 nm as the former have an energy content closely matching the ideal level of chlorophyll excitation. In terms of growth, we are primarily concerned with chlorophylls a and b. The more colourful pigments (carotenoids) serve more of a photoprotective role and do not have a major impact on growth, at least in algae.

Sure re: carotenoids. I was always under the impression that they also act as accessory pigments, extending the range of wavelengths absorbed to drive photosynthesis. As far as the chlorophylls go, based on their absorption cross section, it looks like they absorb more light at lower wavelengths, so I'm not sure what you mean by the ideal level of chlorophyll excitation. Unless you mean the amount of energy transferred to catalyse oxygen evolution? In which case sure... They dump all the excess energy from the higher energy (shorter wavelength) photons off as heat (via internal conversion).

White LEDs as I'm sure you know are a mix of wavelengths. So you can't say a pigment absorbs best at the wavelengths white LEDs emit, since they emit a very broad spectrum.

Yes, of course. I was thinking yellow for some reason. Should've had a coffee pre-post.

Are you a biologist, or just an enthusiast?