This overview is just a brief explanation of aquarium lighting.

To date, climate-based daylight modeling has relied on ray tracing methods, specifically Radiance and its derivatives. There is nothing wrong with this, other than that it has possibly hindered research into alternative approaches.

However, the rate will not increase beyond a certain level of light intensity.References:

, I should note to newer readers of this constantly evolving article that may think there is bias toward high end LED lights, you would only be 1/4 correct, as first I do not recommend the plethora of junk LEDs commonly sold and as well if you were to read this same article circa 2007, I did not recommend ANY LED Light, however technology had increased considerably in this arena of aquarium lighting.

CrxSunny 1000W LED Grow Lights

Figure 1. Spectral sensitivity of the eye in conditions of very low light intensity.

The main ingredient in plants that is responsible for photosynthesis is chlorophyll. Some researchers extracted chlorophyll from plants and studied its response to different wavelengths of light, believing that this response would be identical to the photosynthetic response of plants. However, it is now known that other compounds (carotenoids and phycobilins) also result in photosynthesis. The plant response curve, therefore, is a complex summation of the responses of several pigments and is somewhat different for different plants. An average is generally used which represents most plants, although individual plants may vary by as much as 25% from this curve. While HPS and incandescent lamps are fixed in their spectral output, metal halide lamps are available in a broad range of colour temperatures and spectral outputs. With this in mind, the discriminating grower can choose a lamp that provides the best spectral output for his specific needs.

AGi32 copyright 1999-2017 Lighting Analysts, Inc.

The use of assimilation lighting in greenhouse horticulture has increased considerably over the last decade, both in area as in intensity, leading to an increase in electricity consumption. One of the advantages of LED lighting compared to HPS lighting is the higher efficiency of LEDs. Another advantage is that LEDs emit light with the desired spectral composition (colour).

• Can be paired with other aquarium lighting types.

There are other factors affecting lighting for your aquarium.
For example: You cannot compare the output of a 150 watt Metal Halide to a 150 watt outdoor floodlight. Nor an 85 watt standard incandescent to an 85 Watt 6400 K SHO Bulb.
What I am trying to say is often it comes down to comparing apples to oranges.

Figure 5. Spectral characteristics of a fluorescent black light lamp.

Other aquarium lighting considerations, besides energy input (watts) used are PUR, PAR, Lumens per watt, & even output relative to the size of the light.
For example, a SHO that uses 105 watts but is only 10" placed into a reflector, will be much more efficient as per wattage & space utilized.

Figure 7. Output of the black light per 10nm bandwidths.

We are constantly researching LEDs, which includes real-world use.
We attempt to sell LEDs ONLY proven by researchable FACTS.
As well as those sold by a long term company company with a TRUE commitment to the Aquarium Keeping Hobby, not some "Johnny Come Lately" that are here today then gone tomorrow selling lights to Cannabis growers instead!!

carbon dioxide + water + light energy gives sugar + oxygen

When choosing your aquarium lighting, there's MUCH MORE to consider than just "WATTS PER GALLON". Back in the days of buying your fluorescent cool white or warm white T12 or T8 lights (often even at hardware stores), this 'rule' was quite useful since we were more comparing "apples to apples". Often this would range from 3 to as much as 5 watts per gallon, but this now is quite outdated for most modern lights.