Filtering light through glass

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Barney

Aquarium Advice Activist
Joined
Mar 11, 2003
Messages
189
Location
Clearwater, Florida
Can someone tell me there is a rule about using glass on aquariums with lights? I understand from mixed reviews, glass cut light spectrum/ lumens required for corals and inverts to fully survive.

I can understand in nature, we don't see a sheet of glass over the natural reef bed. I can understand the elimination of glass top and replacing with egg crate. But how do you solve a problem with a piece of glass being used as a support for prevention of glass bowing on the side?

ex. 6 feet long tank, 2 feet of open space for glass top on ends, 2 feet of permantly attached glass in middle.

Three 175 watt MH
Or,
Should I use two 250 watt MH?
 
As for the lighting, the three sounds better to me, only because it is such a long tank, and you can put one every two feet, make things look more even.

With the glass, I dont really know, but I would think if youm had some in the middle you would want it all the way across, for symmetry. Otherwise you might have a tank that looked a little side heavy.
 
HEHE.

Here is my general rule of thumb when it comes to lighting.

When in doubt go with the higher output. :)

I would guess the amount that the glass difuses would be partially accountable for how thick the glass is and the quality.

Really MH bulbs are good for a 2 ft square area so for a 6 ft long tank you should have three bulbs reguardless of wattage. They are in effect spot lights and the watt per gal rule really does not hold very well with them as you could have a 400W bulb over 1 end of a 55 gal tank and you would calculate 7 watts per gal. But on if there is no bulb over the other end that end will not be getting as much light as the end with the bulb. So with MH lights you have to spread the light out more by placing multiple bulbs.
 
I say go with 6 400 watt MH, but since most of us dont have the word Gates, right after the Mr. I would do as much as you can afford, as with most things.
 
HeHe, Yeah I don't have Mr. Gates income....

See, my concern is with the middle plate. Water tend to fill up to it and causes a heavy algae growth; causing change in light spectrum in the center. (I know I have to clean it, but daily, Gee!)

I saw this on a friend tank, he mention it is a pain in b... , But it didn't bother him since it was a african cichlid setup.
 
Well, here is an idea, if your hood has an opening in the center, you can just leave an algae magnet (someting you will need anyway) in that location, and every other night, just clean it. And you will most likely do the whole tank about every four days.
 
keeping the water level below the glass center brace should limit the amount of algae growth. You might get some salt creep that would need to be wipped off every once in a while.
 
I believe I read you have a 180. I would go with no smaller than 2 400W MH. You can place high light (stony) corals directly under the lights and lower light sofites in the center. 400W ballasts and bulbs are not significantly more expensive than 175 or 250. Of course they cost more to run but that is not a concern now since you are now a reef keeper. :mrgreen:
 
Question is, do you have a canopy on this tank? because if you don't, I feel you should go with pendants to light the tank...I don't think it would be so bad cleaning the center piece of glass everyday, I bet you spend more than 15 min a day looking at the tank? I am not criticizing, I just add my daily maint. into the viewing time. I personally believe that you could go more than a day in between cleanings, and the amount of spectrum lost would be so minute between cleanings that it would have virtually no ill effect on the growth of anything in the aquarium giving the length of distance between the lights and the rocks and bottom... You have to remember that most of the rocks and stuff we get comes from depths of over 24inches of water and the spectrum that the corals get is sometimes worse than any spectrum that you are going to provide, due to cloudy weather, silt in the water, and free floating matter that obstructs the intensity..

You will be fine with MH in any configuration as long as you place enough of them to cover the area, choose no less than 5 watts per gal and provide the right K rating..

That will depend on the creatures and inverts you want to keep. They come from different depths and all require a different kind of K rating. Some more intense than others... But that is another story.. Phew.....
 
I wonder if the glass in the center is really needed? The 180 I'm working on at the eye center is completely open on top. It has 1/2 glass though...I don't know if they're all that thick. The 150 at the diagnostic center has two plastic braces on top. I wonder if you could remove the glass and replace it with plastic strips or anything that will not be in your way? As I understand it, the center brace is there to reduce the bow in the top part of the glass. Two smaller ones would, it seems, do an even better job.
The subject of cooling the lights came up in a conversation I had with Champion Lighting the other day. They recommend having a piece of glass or acrylic under the whole lighting system. Their reasoning is that will trap the heat in the box formed by the canopy and the glass so the fans can easily remove it. I didn't think to ask about diffusion. Acrylic is clearer, but would it stand the heat? Also, I think the frequent cleanings that would be required would soon scratch it up to the point that it was more opaque than clear.
Logan J
 
Of course they cost more to run but that is not a concern now since you are now a reef keeper.

Wow Mark, that is a bold statement, I wanna feel that way. Anyways good statements Logan, do you work in an LFS? Sounds like you must.
 
The 180 I have is made by Oceanic.

I can not lower my water level unless I cut some of the overflow lines that is built in on the corners at both ends. If I had to do this, I would have to be precise...

Yes I have a canopy. I built this canopy as part of the whole one piece including the stand. It did come with a oak cabinet stand, but I wanted something to go along with my entertainment system which was made out of pine. The outside is layered of pine wood material. The inside is framed with scrap hardwood.
I'll have a picture posted sometimes around August when I have it completely set up.
The measurement from the top of the water to the top of inside the canopy is 16 inches. I plan to have fans installed to pull out hot air at the top back of the canopy.

As for salt creeps, Already familiar with that. I guess there is no fool proof way to elimate them... :? Unless I am missing something.

For 400 watt MH, what K rating should I look for on this setup?
 
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