New Lighting Question

[ARLO]

Hi All

Now I have a questions about Lighting.. Can someone tell me what setup would be best for my tank? What I really would like (I think) is 2-250W MH and 2-??W either PC/VHO/or T-5 lights. The tank is 49X19X20. So it would be the MH in the middle and then the other lights on the outside of the reflector I think is the normal arrangement. I have been reading up on lighting but it is still new to me, what are the differences in MH wattage I see 10,0000K, 20,0000K etc. etc. Aslo would I be better off to get a retro kit and then just mount the lights to the canopy? Or should I buy separate blue light/actinics and reflectors with ballast?

Please help me understand "Reef" keeping lighting!!

Any and all suggestions welcome.

Thanks as always and see you all on Sat.
Arlo

 

[Mykayel]

Retrofit is the cheapest way to go and if you are at all hand, a DIY hood is very simply.

The 10,000k, 20,000k all refer to the color temperature of the bulb. A 10k is white while a 20k is fairly blue (no antics would be needed).

 

[dela]

If you assume light output to be proportional to watts, then VHO puts out the most light. In reality, it does so, but at a huge penalty in efficiency. Both optical efficiency as well as overall electrical system efficacy since T12's are old technology.

I am setting up the system you are describing by combining 250W 10,000K MH + 96W PCs. The 96W PC should put out a little more light than the 54W T5 even though the T5 is by far the most optically efficient of the three.

There are many color temperatures available. 10,000K I believe is the color of daylight+sunlight at like 1m below seawater (or so). 20,000K is the color of daylight+sunlight at like 20m below seawater (or so.. can't remember the exact depths).

For comparison, incandescent is about 2900K, Halogen 3000, Commercial Metal Halide 3000-4500K. The lower the number the warmer the source.

This is a crappy picture, but it shows the CIE chromaticity diagram with the super-imposed color temperature line.

HTH

 

[Mykayel]

Oh, and if you really wanted to know, the color rating is the color of light that would be emmited by a theoretical black body at that given given timeperature. It has nothing to do with actual temperautre.