Yea, being a single point light source, LEDs will drop off significatly everywhere in the tank except directly under it because the light is travelling at an angle through the eggcrate and since the eggcrate, as you said, has some depth to it, more gets blocked. Having more than 1 LED cluster will make up for some of it, but you will still see a drop.

the $100.00 type of wrasses can jump thru 1/2" egg crate :sad:

Don't know where you checked, but I buy mine at Industrial Plastics. A large 4' X 8' sheet (I use 1/16" thickness lexan) is $90, and you can get smaller pieces. But I buy the whole sheet, as I use it for a lot of things. It is very easy to cut (use a tin snip), drill, form or shape. And you just need to bend a small flange if you want to stiffen up a long edge. I have made all kinds of things for my sump, incl a filter sock holder, and other stuff.

For a tank your size, it shouldn't cost you more than 30 bucks. Then you have a better top than anything you could make out of mesh or egg crate. Plus great light transmission, and reduced heat and water loss. And no more fish loss.

i've never see 1/4" egg crate personally. it would block far more light than the 1/2" already seems to.

An 18"x24" retails for $33 which won't fit my tank (mine is 30" long).

But I was wondering, won't it have the same problem as glass tops? Like salt creeps and get dirty?

BRS has nice DIY video using window frames and 1/4 netting

You're probably looking at HD, which is more expensive, for sure, and I don't think they even carry the 1/16 size. I see there is an Industrial Plastics in Calgary. They should carry it, and be a lot cheaper. Like I said, I can get a full 4' X 8' sheet from them for $90. They might have smaller cut pieces available for less too. But at worst they will cut you a smaller piece, for a small premium.

I clean mine about once a month. It only gets "dirty" if water from a return or pump splashes up someplace. Same with salt creep, only happens where water can splash. But you would have the same with mesh or egg crate, and it would be a lot harder to clean.

Just don't use acrylic or some other kind of plexy. That stuff will bend and warp over time, and has to be a lot thicker (more expensive) to have any strength. And it shatters and cracks really easy.

Well thanks everyone for helping me deciding which route to go. And here is the outcome:

http://i1304.photobucket.com/albums/...ps04d31275.jpg

And in action:

http://i1304.photobucket.com/albums/...ps2a7a8406.jpg

I bought the kit which came with everything (even the mesh) but the problem is since the mesh is black, it is blocking noticeable amount of light. I was thinking of moving to white mesh; will that help?

And now my questions was "how can I feed my fishes!". Since the legs of the light are resting also on the frame so I had to do something. And came up with this idea:

http://i1304.photobucket.com/albums/...psc896505b.jpg

I will put a small egg crate over it to help block that one too :)

Anyway, I have some small spaces uncovered due to the HOBs. Tried with egg crate but didn't seem to help much. Any suggestion about that? :)

Looks good but I would pull the screen and put chicken mesh in its place

White screen will only reflect the light not allow it through

As for the back you could try to zip tie egg crate to the side of screen.

I did try to find chicken mesh but all of the new stuffs coming (atleast to canadian tire) is more than 1/2" holes. That's why I didn't get them.

How about the BRS stuff?