Question about Metal Halide penetration depth?

[cliffrouse11bas]

Just wandering what the general rule of thumb is. Please tell me the penetration depth for vho's and pc's also. I was wandering because I am thinking of setting up a 35 gallon hex tank. The dimensions are 23x20x24, I was just wandering would a 250 be enough or would i need a 400. I am planning on keeping a variety of things clams, and sps, and soft corals also. Thanks alot..

 

[fishman830]

yes what is the pentration depth?

 

[cliffrouse11bas]

The intensity of the light at a given depth. Metal halide is the strongest, pcs are the second, vho is the third, and no is the worst.

 

[fishman830]

i see where does actinic fall in?

 

[cliffrouse11bas]

Not sure I guess it depends on whether it is a pc, vho, or no.

 

[adrian]

Unless your talking about a really deep tank, more than say 30" the corals you plan to keep in relation to wattage of halide will be more of a determining factor than the depth of the tank. You could use a 175 on that tank and be able to keep most corals, but you might want to go with a 250 to be on the safe side. I think a 400 would be overkill. HTH

 

[cprdnick]

Isn't the K at the end of the 10000 or 12000 stated with the bulb the measure of intensity of a given light at a given depth.

 

[adrian]

No, the K which stands for kelvin relates to the spectrum of the bulb. A degree kelvin is a unit of measurement used for rating the color a bulb creates in relation to the kelvin scale. As the kelvin temp increases the bulb gets cooler in color, ie a 65K bulb produces a yellow white color, and 10K bulb produces a white color, and a 20K bulb produces a blue color. Intesnity is measured by lumens. Depth however does play a role in light coloration, but not really in our tanks, in the ocean the water filters certain colors of light so as you go deeper the light appears more blue, but our tanks are much too shallow for that to come into play Actinic lighting is used to mimic this blue light that exists in deeper reef enviroments. HTH

 

[dreeves]

So Adrian...where does the nanometers come in?

 

[jonthefb]

really the only reason to have a halide is if you have a tnak deeper than 30 inches...a 175 is good for less than 24" a 250 for 24-30 and a 400 for anythign deeper
as far as lighting a tank...with halides you need approx 1 per every 2 ft of tank
good luck
jon

 

[adrian]

Nanometers are used to measure actinic light since they cannot be measured in degrees kelvin.