Ehh.. I heard somewhere that you can use moonlights to see octos in the dark? Maybe IR lights?

Some people use moonlights, which would enable you to see the octopus, but in night-like conditions. The other alternative is red leds -octopuses can't see red light. Actually, I prefer the moonlights. They make your tank look beautiful at night, too.

Nancy

I use moonlights...A long strip of blue LEDs. Adds a great visual affect and allows you to watch your cephs at night..

You can use Red lights, since most marine animals do not see this spectrum, but I think the blue moonlights work fine and look great.

I was hoping youd say that :) I kinda wanted one to make it look neat at night too.

Would this sucker work
http://www.marinedepot.com/aquarium_lighting_moonlight_moon_lunar_l amp_aqua_medic.asp?CartId=

Or

http://www.marinedepot.com/aquarium_lighting_moonlight_moon_lunar_l amp_icecap.asp?CartId=

Ive never used one of those products...

I have one of these...
http://cgi.ebay.com/32-Submersible-LED-Moon-Light-Aquarium-Corals_W0QQitemZ7737168506QQcategoryZ463 14QQtcZphotoQQcmdZViewItem

works great!

The real question is whether you want to see the octopus, have a cool looking tank, or have a happy, healthy animal. The blue LED's have a very narrow spectral range peaking at around 470 nm, the same wavelength that you woud find at depths below 30 m in the middle of the day. It is also fairly close to the peak sensitivity of most octopus that have been studied. In short, you are exposing the animal to the spectrum to which it is most sensitive. This is not equivalent to watching an octopus under very subdued lighting. Moon light will have he same spectral qualities, but would be much dimmer. I agree that a tank shimmering in blue light is appealing to our human senses, but it probably seems pretty bright to your favorite octopus.

Roy

Thanks, this is an aspect we haven't considered.

I admit that the tank I'm using moonlights on doesn't have an octopus -when there was an octo in the tank, I used red light. I could see the movements but had to be close to the tank. Still, it worked.

The original concept of moonlight was to use a small LED or two for a tank - the products mentioned in the previous posts have more wattage and more LEDs than I am used to.

Also, I would think that submersible lights could very well become octopus toys, given our past experiences with similar items in the tank.

Nancy

The blue LED's have a very narrow spectral range peaking at around 470 nm, the same wavelength that you woud find at depths below 30 m in the middle of the day. It is also fairly close to the peak sensitivity of most octopus that have been studied.
....
Moon light will have he same spectral qualities, but would be much dimmer. I agree that a tank shimmering in blue light is appealing to our human senses, but it probably seems pretty bright to your favorite octopus.

Very good point-- it's really coincidental that monochromatic blue LEDs happen to look to humans similar to moonlight-- I'd even argue against moonlight having the same spectrum-- it's just blue-dominated, but broad spectrum (reflected sunlight), while the LED is literally photons of only one wavelength. (although white LEDs are really 3 LEDs in one package, so they're 3 distinct single wavelengths). When SCUBA diving, actually, I've noticed I get the same sorts of color-reduction effects as I do in moonlight, for similar reasons... in fact, I like having a small dive light even during the day to illuminate reef bits with full-spectrum light.:rainbow:

It's sometimes hard to remember how differently animals' visual systems are set up to perceive the world, and assume everything sees like we do... even when it's "as different as night and day."

This all made me think of a Moody Blues song/poem:

Cold hearted orb that rules the night,
Removes the colors from our sight.
Red is grey and yellow white,
But we decide which is right.
And which is an illusion?