How many of y'all run moon lights?

[Hans-Werner]

I mean, when you're talking about light hitting the earth's surface, sure... Also, organisms with eyes that occupy the land and air are most definitely disturbed by blue light. However, the water filters out most of the red, yellow, and green light that happens to penetrate the ocean. So there is far more blue, purple, and ultraviolet light, making it to a reef 40 meters down, than red, yellow, and green light. In my mind, this problem only becomes worse with less intense light. I haven't read any studies about the effects of blue light on aquatic species' circadian rhythms, but I would guess that they're adapted to blue light and, therefore, filter most of it out (or their brains have adapted to utilize it in a different way than our brains do up here on the surface)... I could be wrong, though...

There are only few (to my knowledge only two) systems for the typical metabolical reactions to light, phytochrome and the cryptochromes. The cryptochromes regulate circadian rhythms in organisms, from bacteria, yeasts, fungi and algae to mammals including humans. Cryptochromes are sensitive mainly to blue light. Cryptochrome seems to regulate also the coral responses to light.

 

[JNalley]

There are only few (to my knowledge only two) systems for the typical metabolical reactions to light, phytochrome and the cryptochromes. The cryptochromes regulate circadian rhythms in organisms, from bacteria, yeasts, fungi and algae to mammals including humans. Cryptochromes are sensitive mainly to blue light. Cryptochrome seems to regulate also the coral responses to light.

I understand what you're saying, but perhaps you didn't understand what I was saying. Basically, the light hitting the reef, whether from the moon or the sun, is predominantly blue to ultraviolet in nature. It's never pitch black out unless there is significant cloud cover and you're far away from any major cities, or you're in a cave. Even during a new moon, light still exists, however faint. This means that even at night, a reef is getting hit with Blue Light. If it disturbs circadian rhythms in fish, then fish must have evolved to be tolerant up to a certain point, otherwise fish and coral would have no circadian rhythm to speak of, because 99.9999999% of the time, some amount of blue light is hitting the reefs.

 

[Hans-Werner]

I understand what you're saying, but perhaps you didn't understand what I was saying. Basically, the light hitting the reef, whether from the moon or the sun, is predominantly blue to ultraviolet in nature. It's never pitch black out unless there is significant cloud cover and you're far away from any major cities, or you're in a cave. Even during a new moon, light still exists, however faint. This means that even at night, a reef is getting hit with Blue Light. If it disturbs circadian rhythms in fish, then fish must have evolved to be tolerant up to a certain point, otherwise fish and coral would have no circadian rhythm to speak of, because 99.9999999% of the time, some amount of blue light is hitting the reefs.

I don't think the residual light of stars is of much relevance. Commercial "moonlights" have a whole list of faults:

- Much too strong by several orders of magnitude even compared to full moon light at earth or sea surface.
- Much too blue compared to moonlight or expressed different, even more blue light power compared to the complete moonlight, adding more orders of magnitude in disturbing power
- Shining all night and all month. In fact no moonlight is shining all night and all month. Even full moon is rising in the evening shining in a low angle and much weaker than the full moon in zenith at midnight. In fact full moon light is dividing the night in the mid with its strongest light, reducing the length of undisturbed darkness below a critical threshold which other lunar phases don't. Other lunar phases have their highest position and deepest penetration into the water before or after midnight.

None of these specifics is simulated by normal commercial "moonlights".

 

[SudzFD]

My Kessil A500x has a Lunar simulation cycle. I use that. It follows the natural moon phases.

I love this, but don’t have anything like it now. I think it’s a very cool idea. Do you notice any changes in coral or fish behaviors with the lunar cycle simulation?

 

[SudzFD]

I find the “moonlight” setting on my smart farm LEDS to be too bright so I do not use that. Instead I hit a Fluval Smart Aquasky strip light. It’s a pretty cool light and I can ramp up and down the moonlight and incorporate fun affects like lightning storm or other colors easily.

I just have it run from lights out until about 1130pm. Then go total dark until 5am and the fluval kicks on until the main lights come on around 10am. I run it blue spectrum only.

It’s mainly to enjoy the glow of the reef during lights out.

I do think an all dark period is important. During this time my bristle works and cleanup crew really come out and go to work and my fish hunker into their burrows for the night.

 

[AquaLogic]

I love this, but don’t have anything like it now. I think it’s a very cool idea. Do you notice any changes in coral or fish behaviors with the lunar cycle simulation?

At this point no, because the tank has only had coral in it for about a month, but I'll be watching as the months pass.