Egg Crate... narrow side up or down?

[snarkes]

Alright... well i'm trying to keep my gobies from being dare devils and wanted to put egg crate over the top of the tank; however, it has a narrow side and a well... not as narrow side. Does anyone know which side is supposed to face down because the egg crate is supposed to diffuse light right... wanna make sure that it can still do its thing.

Thanks!

[gbtower]

Both ways will reduce the total light entering the tank, but pointing the narrower side down (away from the light) will direct more light into the tank than pointing it up, at least from what I've been told.

[BeanAnimal]

In theory the eggcrate may reduce the total amount of light STRIKING THE WATER SURFACE. BUT! The eggcrate may force more of hte light to strike the surface at an angle much less than the critical angle. So in theory MORE LIGHT PENETRATES the surface of the water. So the effect all depends on the placement and style of the light source(s) above the tank.

Somebody with a quantum meter can do some tests and let us all know what the results are.

[kalare]

<a href=showthread.php?s=&postid=7196314#post7196314 target=_blank>Originally posted</a> by BeanAnimal
In theory the eggcrate may reduce the total amount of light STRIKING THE WATER SURFACE. BUT! The eggcrate may force more of hte light to strike the surface at an angle much less than the critical angle. So in theory MORE LIGHT PENETRATES the surface of the water. So the effect all depends on the placement and style of the light source(s) above the tank.

Somebody with a quantum meter can do some tests and let us all know what the results are.

Didn't Calfo have a thread on this a while back? I think he found that it actually helps. I don't remember what side is supposed to be down though. And of course, he could be wrong, but it's a start. Try searching around over in his old forum (or new)

[snarkes]

Awesome guys! Thanks for all the help

[snarkes]

While i'm here... where is Calfo's forum?

[xdusty6920]

its still there but its not calfos forum anymore. he has decided to move on to other things i believe.

[snarkes]

I looked all over wetwebmedia... and they definitely say that if you turn it upside down that intensifies light instead of blocking it... but never mention if the tapered side is the top or if its the bottom.

[snarkes]

Bummer... I like it when I stumble into some of his old postings and insight.

[GARFVolunteer]

The narrow side goes down to increase the light... That it the intent of egg crate. That is why you find it in the lighting section.

Thanks,

Scott

[snarkes]

Thats what I'm getting from this and other postings... Thanks for your help guys.

[aelvion]

The narrow side goes down to increase the light... That it the intent of egg crate. That is why you find it in the lighting section.

Thanks,

Scott

Sorry for digging up such an old post but I wanted to make sure anyone who stumbled across it (like I just did) didnt get incorrect information.

The consensus of this thread is wrong, eggcrate is installed thin side down in offices to maximize light spread but for an aquarium it should be placed thin side up to maximize light into the aquarium.

quote from Anthony Calfo:

"... prompted by a friend with whom I was chatting about this topic, I'm reminded to start a thread here for folks to refer to in the archives.

Many aquarists commonly use the (drop ceiling) building material known as "egg grate."

This intersecting lighting grid is designed for drop ceiling installations in places where light fixtures are installed. Aquarists use egg grate to cover their aquariums as they block little light from above and nicely keep most all fishes from jumping out at the same time [Smile]

But did you know that there is a top side and a down side to egg grate?

More accurately, there is a spread side and a focus side. That is to say, the interior partitions of the grid are actually tapered to a narrow on one side for the purpose of spreading or focussing light downward, depending on position.

One side measures approximately .07 in thickness while the other measures only .05

So if you are installing egg grate in an office and you are looking for optimizing light spread and energy consumption/efficiency, you'd naturally want maximum spread of light (the tapered side facing downward).

But we want to focus precious aquarium light (expensive to produce!) downward to get as much of it into out aquarium as possible (tapered side up). If you have an aquarium in a dark living room, for example, you may notice that light shines out from the aquarium glass and onto the floor. That is wasted light! But if you put the egg grate over it and focus the light downward, you will notice the light does not spill onto the floor anymore! Remember... tapered side up for aquaria.

The other caveat is that you want to capture the light before it gets a chance to spread out from the fixture itself... so the egg grate must be rather near to the lamps. Fluorescents are easy... they must be close to the aquarium water surface to be remotely effective in the first place (within 3") and the egg grate can be placed safely between them. But metal halide/halogen lamps run very hot and the egg grate can melt, like other plastics. Keep the egg grate several inches away and use cooling fans for hot lamps. That's no inconvenience here because you will need to keep metal halide lamps farther off the surface than fluorescents anyways, and they all typically benefit (literally affecting the color and quality of light) from running cooler (with ans) regardless of egg grate use or not.

FWIW

kindly, Anth- [Smile] "