Lighting question!!!

[herpencounter]

I know this is a very stupid question...

Does the lighting change from 1 inch off the water to 4 or 5 inches?
And how much does it change?

I only have 130 watts on 29 gallons so I need to get as much light as I can down there.

Thanks!

 

[Len]

Lighting's relationship with distance is called the inverse square law. Read here: http://en.wikipedia.org/wiki/Inverse-square_law

Basically, the further from the point source (or something close to a point source), the less light a given spot will receive, but the light energy will be distributed over a greater area. Of course, using reflectors will change the results. That's why good reflectors are very important to maximize light over the area of the tank you want lit.

 

[herpencounter]

So what do you think in your opinion?
Also how would you know if you have a good reflector?

 

[Len]

There hasn't been much tests on reflectors for fluorescents. I'd get one is high polish and multifaceted angles pointing directly down into the tank. I think that's the best you can do. With such a reflector, it doesn't matter too much if it's 1 or 5 inches off the tank the light. Air doesn't attenuate much lighting anyhow.

 

[herpencounter]

I'm just worried that the plate coral or the open brain on the sand wont get enough.

 

[herpencounter]

well I think I can make one of my fixtures I have hold 2 bulbs.
That would give me 34 more watts 164 in total.

What is better 420nm actinic or a 460nm? oops I just looked they only make them 420nm for t-8.

Zoo Med makes a T-8, 10,000k and a...
Zoo Med Actinic 420 T-8.

I think I might be able to make it fit T-12's.
If I can fit T-12's look at this (24in)... this will give me 280 watts give me every coral in the sun (I would think).

This
http://www.drsfostersmith.com/Product/P ... 2004&Nty=1

and this
http://www.drsfostersmith.com/Product/P ... 004&Nty=11

 

[herpencounter]

I know the watts per gallon is not the best rule but I did 7 watts per gallon that’s only 203 watts, so I’m thinking just one 75 watt (205 watts).