# DIY MH Lighting Scale



## jman785 (May 8, 2005)

*Light Spectrum Scale and bulb comparisons*
_by Jared Waites (jman785)_

Many problems with hobbyists, is they don't understand what they are buying. They know it grows coral and algae well..but don't really understand the whole aspect of choosing a good bulb. There are two things, to consider, when purchasing a bulb, I'm not really going to focus on one of them, wattage, I'm focusing on Color Temperature and the comparison of the bulbs. Metal Halide bulbs, should usually be placed, every 24", a perfect tank for a halide, would be a 2'x2'x2' tank Perfect exposure to light, I am blessed enough, to have a tank with these dimensions. Don't get me wrong, this article doesn't cover the totality of the circumstances. There are plenty of other variables that could cause a lot of different results...tank depth/wattage/PAR are just a few things to keep in mind aside from Kelvin.

The 'K' at the end of the color rating, stands for Kelvin, which measures color temperature. The higher the Kelvin, the more cooler (bluer/actinic) the color of light given off by the bulb.

6500k = yellow tint to the color of the light such as the Iwasaki bulb. - Great for growing, although doesn't show coloration of corals as well as the others, but offers excellent growth.

10k - in between 6500k and 20k, great all out coloration and growth, not as good of coloration as 20k, and not as good of growth as the 6500k offers.

20k - not as good growth as the 6500k, but offers maximum coloration and is more blue.

I made this article to help people decide what they want to do with their tanks. 6500k is mainly for grow-out unless supplemented by actinic, or 10 or 20k bulbs, to add more blue coloration to the tank.

6500k is also the closest to natural sunlight you can get, with the good growth it offers.

Iwasaki - 6500k
Ushio - 10k
Sunburst - 12k
Radium - 20k


























Alot of this information, can cause heated debates, although from many experiences, by myself and others, I believe this information to suit you best, and hopefully you'll understand more about the bulbs, after reading this, and it can help you make a better selection in the future. Good luck









Pictures by N. Morris


----------



## Ægir (Jan 21, 2006)

GREAT POST, i would like to add that you can also create combination's of bulbs to suit your growth and color needs!

I run 2 175w USHIO 14K bulbs (sides), 1 400w SPS (South Pacific Sunlight) 10K bulb (center) and 3 48" VHO Super Actinic bulbs to fill in the colors...

Plenty of glow!


----------



## jman785 (May 8, 2005)

On my 150 gallon (48x36x20), the one I'm now turning into a Pygo tank, I had dual 400 watters on it...1/2 HP chiller.









I miss those days, but I'm tired of boiling water haha


----------



## nismo driver (Jan 27, 2004)

very good write up.

a few more considerations would be the reflector and ballast. most people dont realise that the ballast can effect color out put of the bulb and a good reflector can really get you the most out of the bulb.


----------



## jman785 (May 8, 2005)

Good point,

Lumenarc and LumenBright reflectors are by far the best reflectors you can have for throwing light over a reef.

As far as ballast goes,

I use Advance Pulse start ballasts (http://www.1000bulbs.com/250-Watt-Metal-Halide-5-Tap-Ballast/), with a mogul socket.

Here is my old setup that I just sold.

Here is a stainless steel starter box that housed both of my 250 watt halide ballasts and caps, as well as my Intermatic timer:









Here is the timer on the door of the starter box:









Here is a picture of the wiring and ballasts:









I had used heavy duty wire with heavy insulation (I forgot what gauge, it would be basically like a heavy gauge extension cord, it came from a Hayward pool light, I own a pool company and ordered too long of a run and had a lot of extra cord) that went to 'extension cord' ends, so I had quick disconnects to separate the canopy, although I had enough slack to take the canopy off and set it on the ground.


----------

