eggcrate and par reduction

flyyyguy · 02/25/2008, 12:52 AM

I heard someone say as if fact the other day that one layer of eggcrate will reduce the par by around 50%

Visually.......im having a hard time buying it. visually, 3 pieces stacked on top of each other crossed in such a way that you are blocking as much light as possible doesnt even appear like its blocking that much.

yay or nay?? if nay.......how much does it block??

suppressivefire · 02/25/2008, 12:56 AM

I agree with you i don't see how it could block 50% par with one sheet. IMO it would block 15% or less.

mile sq. reefer · 02/25/2008, 12:56 AM

If it blocks PAR, my corals dont seem to know it.

flyyyguy · 02/25/2008, 01:03 AM

I almost want to post a link to the thread as the guy was something else......you should have heard him...... LOL

Ill spare him. But I would like to know how much it indeed blocks....

twon8 · 02/25/2008, 01:10 AM

i've heard it actually increases light as it focuses those beams at an angle back down. no way it could decrease light

HBtank · 02/25/2008, 01:22 AM

I swear I heard it has two sides.

One focuses light, and the other diffuses it. It is due to a slight taper on the eggcrate in one direction.

I never looked at it close enough to see, and do not use it that way, but I read it somewhere.

twon8 · 02/25/2008, 01:23 AM

Quote:

Originally posted by HBtank
I swear I heard it has two sides.

One focuses light, and the other diffuses it. It is due to a slight taper on the eggcrate in one direction.

I never looked at it close enough to see, and do not use it that way, but I read it somewhere.

you are correct, one side is a tiny bit wider.

flyyyguy · 02/25/2008, 01:25 AM

Youre right it does......i knew that but as ive never used it that way before either the other day when I was trying to "diffuse" some light i didnt even think about which side was up...

being as bright as it was I imagine I had it the wrong way to stop anything.......

suppressivefire · 02/25/2008, 01:36 AM

Chrome egg crate?

flyyyguy · 02/25/2008, 01:40 AM

I probably posted this in the wrong forum.........I tried looking online at suppliers to see if I could find any info....no luck but im sure the numbers are somewhere for both fat side up and skinny side up....

twon8 · 02/25/2008, 02:08 AM

found this
from Anthony Calfo at
http://forum.marinedepot.com/Topic24384-13-1.aspx

"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"

flyyyguy · 02/25/2008, 09:46 PM

good info Anthony.

bump for numbers tapered side up vs down......

barjam · 02/25/2008, 11:12 PM

I remember and article where Dana Riddle showed it increased light a tiny bit... can't find it though.

02/25/2008, 12:52 AM	#1
flyyyguy King of the white corals Join Date: Jun 2006 Posts: 5,239	eggcrate and par reduction I heard someone say as if fact the other day that one layer of eggcrate will reduce the par by around 50% Visually.......im having a hard time buying it. visually, 3 pieces stacked on top of each other crossed in such a way that you are blocking as much light as possible doesnt even appear like its blocking that much. yay or nay?? if nay.......how much does it block??

02/25/2008, 01:03 AM	#4
flyyyguy King of the white corals Join Date: Jun 2006 Posts: 5,239	I almost want to post a link to the thread as the guy was something else......you should have heard him...... LOL Ill spare him. But I would like to know how much it indeed blocks.... __________________ I like holding hands, snuggling, and long walks on the beach

02/25/2008, 01:10 AM	#5
twon8 Formally registered membe Join Date: Oct 2003 Location: slightly sw of richmond, va Posts: 5,920	i've heard it actually increases light as it focuses those beams at an angle back down. no way it could decrease light __________________ Anthony Richmond Reef Club "and as things fell apart, nobody paid much attention." Not building a wall but making a brick Current Tank Info: 300g DD display, 60g frag tank

02/25/2008, 01:22 AM	#6
HBtank Premium Member Join Date: Jan 2006 Location: Huntington Beach, CA Posts: 2,957	I swear I heard it has two sides. One focuses light, and the other diffuses it. It is due to a slight taper on the eggcrate in one direction. I never looked at it close enough to see, and do not use it that way, but I read it somewhere. __________________ 80g Aiptasia dominated reef tank.. with fish and now a bunch of berghia! Current Tank Info: 80g tank, re-starting a reef after a zoanthid nudibranch plauge, followed by months of steady and unstoppable STN/RTN, crashed; stayed FOWLR for a couple years, currently an aiptasia dominated reef tank with fishies and BERGHIA

02/25/2008, 01:25 AM	#8
flyyyguy King of the white corals Join Date: Jun 2006 Posts: 5,239	Youre right it does......i knew that but as ive never used it that way before either the other day when I was trying to "diffuse" some light i didnt even think about which side was up... being as bright as it was I imagine I had it the wrong way to stop anything....... __________________ I like holding hands, snuggling, and long walks on the beach

02/25/2008, 12:56 AM	#2
suppressivefire Registered Member Join Date: Mar 2007 Location: at the drag strip Posts: 1,948	I agree with you i don't see how it could block 50% par with one sheet. IMO it would block 15% or less.

02/25/2008, 12:56 AM	#3
mile sq. reefer Registered Member Join Date: Apr 2006 Location: NJ Posts: 2,045	If it blocks PAR, my corals dont seem to know it.

02/25/2008, 01:36 AM	#9
suppressivefire Registered Member Join Date: Mar 2007 Location: at the drag strip Posts: 1,948	Chrome egg crate?

02/25/2008, 01:40 AM	#10
flyyyguy King of the white corals Join Date: Jun 2006 Posts: 5,239	I probably posted this in the wrong forum.........I tried looking online at suppliers to see if I could find any info....no luck but im sure the numbers are somewhere for both fat side up and skinny side up.... __________________ I like holding hands, snuggling, and long walks on the beach

02/25/2008, 02:08 AM	#11
twon8 Formally registered membe Join Date: Oct 2003 Location: slightly sw of richmond, va Posts: 5,920	found this from Anthony Calfo at http://forum.marinedepot.com/Topic24384-13-1.aspx "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" __________________ Anthony Richmond Reef Club "and as things fell apart, nobody paid much attention." Not building a wall but making a brick Current Tank Info: 300g DD display, 60g frag tank

02/25/2008, 09:46 PM	#12
flyyyguy King of the white corals Join Date: Jun 2006 Posts: 5,239	good info Anthony. bump for numbers tapered side up vs down...... __________________ I like holding hands, snuggling, and long walks on the beach

02/25/2008, 11:12 PM	#13
barjam Registered Member Join Date: Jan 2002 Posts: 1,695	I remember and article where Dana Riddle showed it increased light a tiny bit... can't find it though.