Mirrored lighting in reef tanks?

[irahmatulla]

Hello All! Sometimes I really feel like a newb when I am getting out side of my experience and the interwebs can be greatly confusing at times.

So, a while back right after a move (in which my 90g broke) my 400w MH burnt out. The ballast like....literally caught on fire. It was positioned over my 60g cube (24/24/24) and lit up my life! When it went out, I was on hiatus from reef purchases as the move had just cleaned me out. Very quickly most of my sps and clams bit the dust. (I had about 54w of T5 over it that used to light my 29g) I was near quitting completely but my fish and softies were doing fine.....long story I know. IN short, I recently purchased a 175w MH brand new bulb slightly used ballast and rigged my old reflector on to it. I was stoked driving home thinking.....sweet I can now put my T5 (brand new bulbs) over my 29 and start a second tank. Man was I let down.....this light alone barely lights the top half of the tank, and bright as a.....well...beauty school drop out. Is there any way without going out and blowing another $200 to intensify this light? Or is there some form of warm up time for the brand new bulb where in a week it will be like a beach in my foyer again? I was thinking of making a tapering hood lined with mirrors to maybe try and amplify the light, but I do not want to undergo a worthless project. I also know with the shape of something like that on an unbraced tank, I would be putting additional pressure on the walls and this may be a terrible idea. Can I maybe make a faux pendant with mirrors and suspend it somewhat like a chandelier. Please, I know if I try and return it I will lose half of my money to the LFS.

 

[picoreefguy]

instead of using mirrors that are big and bulky and heavy see if you can find a sheet of mylar it has a mirror finish and is super light weight coralife uses it for the reflectors in some of their t5 fixtures

 

[purplegorilla]

The salt environment will cause the mirror to delaminate and the silver to tarnish. Better off with a polished aluminum sheet or something lighter and less maintenances.

 

[ichthyoid]

Spend $50 on a used electronic 250 watt ballast and $50 on a Phoenix bulb.

Sell the 175 rig on here to offset the cost.

JMO

 

[nassar0505]

I'm pretty sure mirrors are a bad choice for light reflection. Though it seems like it doubles you're light the reflection of light energy is used wrong with mirrors. .02

 

[ichthyoid]

Studies using various reflection materials have shown that white paint has almost as good reflection properties (>90%) as those German made metal reflectors, and costs much less.

Protecting any reflective material from salt water splatter and dust is always a concern. These will greatly reduce reflection.

If heat is a concern, such as when using metal halides, Rustoleum makes high temp spray paints for grills, light fixtures, etc. Be careful if using wood though. You can always use aluminum flashing to cover the inside of a canopy, then spray paint it white using the high temp white paint.

**Any enclosed canopy using a high temp light source NEEDS to be vented, and preferably have active cooling such as fans. Blowing air directly on MH bulbs usually affects their performance, both spectrum and efficiency.

 

[ichthyoid]

2nd law of thermodynamics, says that you can never get more out than you put in, in fact you can't even break even.

So, there is no reflector in existence that will 'amplify' your light, it won't even reflect it all. There is always some loss due to the above law.

Some are merely more efficient than other alternatives.

 

[ichthyoid]

Focus yes, amplify no.

I know this is semantics, but there is a BIG difference!

Focusing takes the available light, and directs it over a smaller area. This makes it more 'intense', though you cover less area.

Focusing sunlight using a magnifying glass is a perfect example (fun too!)

(technically light intensity it is known as 'irradiance': irradiance = power/area)

 

[skriz]

A mirror will actually Have the opposite effect. The light will have to travel through glass twice (once to get to the reflective material and once more on its way back).

Like Bill said, you're better off using white paint.

 

[ichthyoid]

I stand by my statements.

I believe that you are mistaking the recapture/redirection of light which was 'lost', with amplification.