Scientific Light in Canopy Question

[the curious]

OK, so I am in the middle of building a canopy for my 90 gallon. I was thinking about painting the inside black, like the outside will be painted. Then I started thinking about biology class...

If I remember correctly, the color we see on an object is the only color that isn't absorbed. That being said, if I were to paint my canopy black, every other color would be absorbed except black, which is being bounced off the object, therefore allowing me to see it as black.

So...should I paint the inside of my canopy white? Scientifically it seems that if the inside of my canopy were painted white, the super white light coming off of my LEDs would be "bounced" off into the water, rather than absorbed.

I have a feeling that this might just not really make any substantial difference, since we are talking about 450 watts of LED light only 12" from the top of the water. I just had the thought and wanted input from someone more knowledgeable than myself.

Thanks for any input

 

[ripped tide]

Line that thing with tin foil!

 

[the curious]

I thought about that. I know it actually burns the leaves and is not good for growing indoor...tomatoes.

I really don't want to use any reflective material anyway, I'd like to stick with paint.

BTW, your signature is hilarious Ripped Tide. I couldn't agree more

 

[ripped tide]

Thank you!!! Lol

I think the white paint should do the job.

 

[rdnelson]

Actually, black is an absence of light. I painted the inside of my canopy white.


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[ripped tide]

What about blue? If the blue pigment absorbs the other spectrum and reflects blue, it may give the tank a "more blue" look

 

[the curious]

Ripped Tide;856195 wrote: What about blue? If the blue pigment absorbs the other spectrum and reflects blue, it may give the tank a "more blue" look

My LEDs are already very blue, so I'm trying to get more white. It makes sense that blue paint in the canopy would give a more blue feel to the tank though.

I'm wandering how the guy in the paint dept. of Home Depot would react if I asked for some actinic blue paint...preferably in the 460nm realm.

Edit:

rdnelson99;856194 wrote: Actually, black is an absence of light. I painted the inside of my canopy white.

Have you had any issue keeping the white clean, and do you have glass tops?

 

[elfloyd]

Light travels in a straight line. LEDs, at max, will produce 180 degrees of light. Most LEDs have optics to focus the light into a 60, 90, or 120 degree range. Nothing of importance should bounce around the canopy.

MH lights can be different because the bulbs produce 360 degrees of light. But, they should have a reflector the sends the light into the tank.

Granted, there could be some light leaking from another part of the lighting fixture, but I believe any light bouncing around the canopy is for our benefit... seeing in the canopy. Very little is focused into the tank.

 

[rdnelson]

the curious;856197 wrote:

Have you had any issue keeping the white clean, and do you have glass tops?

No problem keeping it clean and no I do not have a glass top.

I agree with Larry's (elFloyd) statement completely. What is reflected from the canopy will not benefit the par seen by the coral and only serves to make things easier for my old eyes. .


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[the curious]

That makes sense. Like I said, I thought it might not make much of a difference in my situation, just wanted to get some more input on the idea.

I think I'm gonna go with the black so that I don't blind my girlfriend every time I open the canopy, which is fairly often.

Thanks for the input guys

 

[clay4au]

may want to prime with Kilz or use a clear coat to help protect the wood

 

[sewer urchin]

Line that thing with tin foil!

May help keep the aliens out as well!

I painted mine white, at the time had MH with crappy reflectors, made little difference. It did make the canopy look cleaner.

+1 on the Killz idea, Good call Clay.

 

[ichthyoid]

To the OP-

You were almost right. The color of objects is determined by the wavelengths that are reflected.
(you said 'not absorbed', but there is a difference)

The inside of your canopy would best be painted with a flat white paint. That will give about 90% reflectivity for all visible wavelengths.

FWIW-
Colors absorb their 'complimentary colors', which are the colors opposite those on the color wheel.