Too much moon light?
- Thread starter Colin
- Start date
BeanAnimal
Premium Member
Is it keep the animals awake? Are the corals staying extended under it?
BeanAnimal
Premium Member
jeff and colin...
moonlight IS sunlight. Therefore it is "white" light. We think of it as being blue, but this is only because the blue wavelengths have higher energy. In low light, esp underwater, the blue wavelengths are the only ones to make it deep enough to see.
The 410-520 nanometer wavelengths are what we would commonly consider "blue". The Actinic bulb likely falls well within this range. Wavelengths above 520 are easily absorbed by the water and/or not reflected or transmitted as well in air. Our eyes see the higher energy blue wavelengths better in low light as well. We as humans see from about 400nm to about 700nm (blue to red). Remember the old "dark room" safe lights for black and white film? They were RED because red is low energy and would not expose the film. Why do submarines and dark workspaces use RED light? Because it is low energy and easy on the eyes. It should be no big surprise to find out that our critters do not see red very well either! You can use brighter red lights and not disturb the critters for night viewing. The bluer the light, the more they will see it.
Ever wonder why fire engines are no longer RED and instead are GREEN (actually chartreuse yellow, a mix of light between 560-570 nm if I recall). Because that is what our eyes are most sensitive to in daylight. The CONES in our eyes do not function in the dark. So RED fire engine appear to be BLACK!! A BLUE fire engine would be hard to see in the day and BLACK at night (look up 'Purkinje Effect')
So where does this leave us?
Blue can be seen by your critters, the brighter the more they will notice. But to some extent the critters are used to blue as that is what filters into the water at night and is though to help trigger spawning etc. BUT remember moonlight comes and goes with the phases of the moon.
Red will illuminate your tank at night and allow you to see all kinds of stuff. For the most part, the critters will be clueless.
Notice how under the moonlight, the YELLOW AND GREEN colors are fairly easy to see and the rest look black!
There, more than you wanted to know.
Bean
moonlight IS sunlight. Therefore it is "white" light. We think of it as being blue, but this is only because the blue wavelengths have higher energy. In low light, esp underwater, the blue wavelengths are the only ones to make it deep enough to see.
The 410-520 nanometer wavelengths are what we would commonly consider "blue". The Actinic bulb likely falls well within this range. Wavelengths above 520 are easily absorbed by the water and/or not reflected or transmitted as well in air. Our eyes see the higher energy blue wavelengths better in low light as well. We as humans see from about 400nm to about 700nm (blue to red). Remember the old "dark room" safe lights for black and white film? They were RED because red is low energy and would not expose the film. Why do submarines and dark workspaces use RED light? Because it is low energy and easy on the eyes. It should be no big surprise to find out that our critters do not see red very well either! You can use brighter red lights and not disturb the critters for night viewing. The bluer the light, the more they will see it.
Ever wonder why fire engines are no longer RED and instead are GREEN (actually chartreuse yellow, a mix of light between 560-570 nm if I recall). Because that is what our eyes are most sensitive to in daylight. The CONES in our eyes do not function in the dark. So RED fire engine appear to be BLACK!! A BLUE fire engine would be hard to see in the day and BLACK at night (look up 'Purkinje Effect')
So where does this leave us?
Blue can be seen by your critters, the brighter the more they will notice. But to some extent the critters are used to blue as that is what filters into the water at night and is though to help trigger spawning etc. BUT remember moonlight comes and goes with the phases of the moon.
Red will illuminate your tank at night and allow you to see all kinds of stuff. For the most part, the critters will be clueless.
Notice how under the moonlight, the YELLOW AND GREEN colors are fairly easy to see and the rest look black!
There, more than you wanted to know.
Bean
