Help, they are laughing at me Anthony :)

It should be the latter, the intensity of light in a given area increased 25%. And I believe that area was the test 'tank' (I am unsure if this was done on a real aquarium or simply a marked off area similar in size to an aquarium).
 
But a specific area of the tank?

I think that what we're seeing here is an increase in intensity in the areas that normally wouldn't be as brightly lit because of the reflective qualities of the water's surface eg. the front 6 inches of a 24 inch deep tank.

The areas directly under the point source lighting should have a lower output. Due to the "the egg-grate (obviously) does block some light" statement from Dana.

To say that it increases the intensity of light by 25% is a little misleading I think. Because actually while increasing it by 25% in the "focused area" you're decreasing it by at least that much in the areas directly under the bulb.

Interesting topic.
 
confused

confused

what is this thread about? I followed the links but havent the foggiest about eggcrates? Do you mean like eggcreate at supermarket or something different? Please a little guidance here to uninformed.

thanks
Dave
 
Dave, you would find eggcrate in the lighting department at most home improvement stores. Pic below. :) You might do a search here on RC in the photo gallery showing how some people cut it to fit the top of their tanks. Also, you will see it used as a tray to hold frags.

eggcrate.jpg
 
so to work best the eggcrate should be 3" away, even if using MH lighting?

Wouldn't that melt the eggcrate?
 
egggrate is pretty rigid plastic, doubtful it would melt. I would guess it would become brittle over time and begin to crack/fall apart.

Goby
 
Egg crate is also used in many buildings. If you look up at the lights... a lot of time the egg crate is right below the lights.... and think.. those lights are on very long and on everyday.

The lighting section is where you will find egg crate in a store.... I know I had trouble explaing what it was to an employee.
 
I like the idea of the "ensquaring" of the tank. That way you get less light spill from the sides, but dont lose your intensity directly below the fixture.
Eggcrate is made of styrene. I cannot remember the softening temperature of it, though, sorry.

I never took the original statement to mean that the lights put out 25% more power. The eggcrate obviously only helps focus the light that gets reflected back.
Thanks for the links, James!
 
I made a concerted effort today when I was going around for work to look at the eggcrate fixtures I saw. Everyone I saw had the thick side pointing up. This is opposite of what Dana Riddle encouraged. In this manner, it did seem to block some of the light and diffuse the rest. But, with the thin side up, it would block very little of the light and focus it all straight down.
 
superedge88 said:
I have the thick side up, is this wrong?!!
Yes, that blocks some light and disperses the rest. What you want to do is 'capture' the light and focus it downward into the aquarium. To do this, point the thin side up.
 
Yes, that blocks some light and disperses the rest. What you want to do is 'capture' the light and focus it downward into the aquarium. To do this, point the thin side up.

Is there a difference you could actually see easily?? Or do you think it could only be measured with a meter?

Because I have been using eggcrate over my tank for quite a while just to keep fish from jumping out. It's cut into 2 pieces, separated at the center brace. I never even realized there were 2 sides to eggcrate until I read this thread. So last night I check and see that I have one piece on wih thin side up and 1 side on with thin side down (they HAVE always been used in the same orientation, because certain sections cut-out for equipment necessitate in which direction the eggcrate can be placed on).

I have never noticed any difference with the light on the 2 sides , and I tried last night turning them around (even though they dont fit perfectly) and still dont see a difference there either.
 
To make a significant difference, the eggcrate must be within several inches of the light source. By placing is on top of the aquarium (to aid in keeping jumpers in the tank), the light that could have been directed into the aquarium has already been lost to the room. As such, it probably does not help or hurt much either way.
 
My eyeball measurement yesterday is that the fixture is between 5 and 6 inches from the eggcrate.

BTW, it is a SLS Maristar, 250w HQI, supported over the tank using leg brackets (no canopy).
 
So is this the reflective eggcrate being used here, or the plain white?

Has anyone had any heat-related issues with the eggcrate? I would think that 5 inches below a 250W HQI, would soften it and make it bow. Another guess on my part is that if the reflective eggcrate is used, the heat could speed up the flaking of the reflective material.
 
This is just the white eggcrate. Honestly, it does not even get warm to the touch. These same 2 pieces have been on my tank for over a year.

I believe the white relects away some of the heat. I posted in another thread about how the eggcrate keeps the tank a couple of degrees cooler. When I forget to put it back on after doing maintanence, I have noticed the tank temperature inching up a bit.
 
That's interesting as heck, I gotta say. I had eggcrate over my 120 to keep the Anthias in water. But when I upgraded to 250W HQI's the heat scared me. I thought it might soften and actually collapse into the tank while I wasn't home. Shows how paranoid I am. My paranoia did cost me 2 anthias. It would've been a third, if he hadn't jumped 2 feet right into my 125! Gotta give this a shot.
 
As far as worrying about the stuff melting, dont give it a second thought.

I would just like to figure out these lighting intensity questions.
 
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