How well does water absorb infrared and visible light?

foob · 02/03/2008, 07:06 PM

Just curious, how well does water absorb infrared and visible light? Say, versus air.

Suppose a coral is being burnt by the intensity of the light, and I can either raise the light or increase the level of water (which reduces the amount of air between), which option is better?

Basically I want to maintain the intensity of the visible light but decrease infrared rays. Other than low-E glass/film, any other cheap way?

old salty · 02/03/2008, 07:47 PM

Water is denser than air, and absorbs visible light more so than air. If you go 500 feet under the ocean, it's pitch black (there is several miles of air above you and you can still see pretty well.) Water tends to filter out reds faster than blues, so I would say infrared is quickly reduced in water due to having a larger wavelength than, say ultraviolet light.

To answer your question, water will work better than air.

foob · 02/03/2008, 07:56 PM

Thanks that information helps a lot.

02/03/2008, 07:06 PM	#1
foob Registered Member Join Date: Nov 2004 Location: Lafayette, IN Posts: 471	How well does water absorb infrared and visible light? Just curious, how well does water absorb infrared and visible light? Say, versus air. Suppose a coral is being burnt by the intensity of the light, and I can either raise the light or increase the level of water (which reduces the amount of air between), which option is better? Basically I want to maintain the intensity of the visible light but decrease infrared rays. Other than low-E glass/film, any other cheap way?

02/03/2008, 07:47 PM	#2
old salty Genius Join Date: Jun 2005 Location: The Island of Misfit Toys Posts: 3,131	Water is denser than air, and absorbs visible light more so than air. If you go 500 feet under the ocean, it's pitch black (there is several miles of air above you and you can still see pretty well.) Water tends to filter out reds faster than blues, so I would say infrared is quickly reduced in water due to having a larger wavelength than, say ultraviolet light. To answer your question, water will work better than air. __________________ "The man who reads nothing at all is better educated than the man who reads nothing but newspapers." Thomas Jefferson Current Tank Info: Out of the marine aquarium hobby

02/03/2008, 07:56 PM	#3
foob Registered Member Join Date: Nov 2004 Location: Lafayette, IN Posts: 471	Thanks that information helps a lot.