What defines moderate lighting versus high lighting

[Leetch]

While reading up on different coral species that I eventually plan to to put in my tank (when it ages more), I notice that most require "moderate" or "high" lighting. What defines moderate versus high. Is it total luminosity at the position of the coral?

I have a 29 gal tank with 4 bulb 96w T-5 lighting (each with individual reflectors), is that considered moderate?

I must say, there is a whole world of information on reef tanks and I feel I've only touched the tip of the iceberg. I look forward to learning but sometimes it's hard to do while at work

[Parrothead]

the lighting you have for your size tank will allow you to keep just about anything you will want including clams, etc.......

[Ninong]

While reading up on different coral species that I eventually plan to to put in my tank (when it ages more), I notice that most require "moderate" or "high" lighting. What defines moderate versus high. Is it total luminosity at the position of the coral?

This is just a relative term. There is no real definition of what people mean when they say high light or moderate light. Speaking in terms of metal halide lighting, high light is generally considered to be either 400w lamps or very good 250w lamps with the coral placed somewhere in the tank where it receives "high" light, whatever that means.

Moderate lighting, speaking in terms of metal halides again, was generally accepted to be 175w lamps or 250w lamps that were not say 10,000K. In other words, the Kelvin rating also affects the intensity rating (high or moderate) of the lamp in question. A very good 10,000K 250w HQI DE lamp could be more than twice as intense as a 250w 14,000K or 20,000K lamp. So that 250w 14,000K lamp would be considered moderate lighting while the 250w 10,000K lamp would be considered high lighting.

Some older references break it down as 400w metal halides equalling high lighting and anything less meaning moderate lighting but some of the better 250w 10,000K HQI DE lamps are just as good as some 400w lamps.

A 150w or 175w metal halide has always been considered moderate lighting, provided the coral is placed high enough in the tank. VHO lamps were always talked of as representing moderate lighting and normal output fluorescent lamps were considered low lighting.

All of the above varies depending on the individual lamp and the type of reflector. That was all before HO T5 fluorescents. Most people consider HO T5 fluorescents in individual reflectors to equal moderate to high lighting, provided the coral is positioned properly. I wouldn't attempt to light a 36" tall tank with T5s, for example. That would call for 400w metal halides to equal high lighting and 250w halides to equal moderate lighting.

I have a 29 gal tank with 4 bulb 96w T-5 lighting (each with individual reflectors), is that considered moderate?

Overall, yes, that would be considered moderate. However, anything that is positioned properly could be considered as being under high lighting. Your light intensity 8" below the water's surface in the middle of your tank will be three times as high as your light intensity near the bottom of the tank toward the ends of the tank or the front of the tank, depending on the position of your fixture.

I wouldn't be concerned if I were you. Some SPS and crocea clams should be placed in the center of the tank and in the upper third of the rock structure if you want to tank advantage of your best light intensity.

In Post #4 in this thread, I give examples of high intensity lighting with just T5s and very high intensity lighting with 400w metal halides.

The light fixture used for the T5 setup is a very expensive, ATI Supermodule with ten 80w HO T5s in individual reflectors. That's a VERY nice fixture but it's also very pricey.

[Leetch]

This is just a relative term. There is no real definition of what people mean when they say high light or moderate light. Speaking in terms of metal halide lighting, high light is generally considered to be either 400w lamps or very good 250w lamps with the coral placed somewhere in the tank where it receives "high" light, whatever that means.

Moderate lighting, speaking in terms of metal halides again, was generally accepted to be 175w lamps or 250w lamps that were not say 10,000K. In other words, the Kelvin rating also affects the intensity rating (high or moderate) of the lamp in question. A very good 10,000K 250w HQI DE lamp could be more than twice as intense as a 250w 14,000K or 20,000K lamp. So that 250w 14,000K lamp would be considered moderate lighting while the 250w 10,000K lamp would be considered high lighting.

Some older references break it down as 400w metal halides equalling high lighting and anything less meaning moderate lighting but some of the better 250w 10,000K HQI DE lamps are just as good as some 400w lamps.

A 150w or 175w metal halide has always been considered moderate lighting, provided the coral is placed high enough in the tank. VHO lamps were always talked of as representing moderate lighting and normal output fluorescent lamps were considered low lighting.

All of the above varies depending on the individual lamp and the type of reflector. That was all before HO T5 fluorescents. Most people consider HO T5 fluorescents in individual reflectors to equal moderate to high lighting, provided the coral is positioned properly. I wouldn't attempt to light a 36" tall tank with T5s, for example. That would call for 400w metal halides to equal high lighting and 250w halides to equal moderate lighting.


Overall, yes, that would be considered moderate. However, anything that is positioned properly could be considered as being under high lighting. Your light intensity 8" below the water's surface in the middle of your tank will be three times as high as your light intensity near the bottom of the tank toward the ends of the tank or the front of the tank, depending on the position of your fixture.

I wouldn't be concerned if I were you. Some SPS and crocea clams should be placed in the center of the tank and in the upper third of the rock structure if you want to tank advantage of your best light intensity.

In Post #4 in this thread, I give examples of high intensity lighting with just T5s and very high intensity lighting with 400w metal halides.

The light fixture used for the T5 setup is a very expensive, ATI Supermodule with ten 80w HO T5s in individual reflectors. That's a VERY nice fixture but it's also very pricey.

Great - Thanks for the info!!!