Think LED has 166% more lumins/watt
So the 48" one is equal to a single 27W CF bulb, not nearly enough for a reef
"Focused Lumens;
It is also noteworthy that even the lumen output can be deceiving when considering aquarium lights; LED are a good example of this as these newer technology lights have extremely focused light energy with little essential light energy lost (such as by Restrike), unlike almost every other type of aquarium light currently available. With this focused energy a LED often requires half the lumens (or often even less) to provide essential light energy (such as PAR) to plants, corals, etc. The newer generation LED lights have considerable less loss of lumens at 20 inches than a CFL light (as per tests that show 166% more lumens for the same wattage LED as compared to a common CFL of equal wattage). As another example, think lasers, although not nearly as focused as a laser, modern LED emitters (such as the Aqua Ray) are much more focused than other types of commonly used aquarium lights.
Caution as to using Lumens as a useful measurement of Light Output:
While lumens are a important useful measurement for standard household light bulb comparison, it is only a part of the equation for aquarium use, especially when this measurement is applied to new technology lights employed by aquarium keepers (such as LEDs).
As an example of just one aspect where the lumen measurement falls short is when Kelvin is considered; a bulb emitting 1000 lumens at a color temperature of 20,000K will not emit as much PAR as a bulb emitting 1000 lumens at 6500K.
WATTS:
Watts equal one joule of energy per second. For us, it's a measurement of how much energy our light fixture is using NOT of light output! This why the 2-3 watts per gallon for FW plants (3-5) for reef can be deceiving, and this rule is only a starting point similar to the 1 inch of fish per gallon "rule". This archaic rule was more accurate when all that was used were T12 lamps which is what this rules is based on.
Keeping this in mind the average T12 has a lumens per watt rating of 40, which means you would need half as many watts of a bulb that produces 80 lumens per watt (assuming PAR, Kelvin and other aspects are equal)
The term "watts per gallon" is getting more archaic as newer T-2, T-5, compact Fluorescents, the SHO, and especially the new reef compatible LED lights have more watts spread over less distance. Keeping this in mind; 'watts', when applied to a standard fluorescent tube are spread over longer bulbs as the wattage increases. For instance a standard 30 watt T 8 bulb is 36" while a standard 20 watt T-8 bulb is 24". For high light requirements such as plants or reefs, at least 1 inch per watt is required when comparing tube style fluorescents bulbs.
Many high output light such as the Metal Halide or the more economical SHO PC bulbs use a lot of watts in a small amount of space. The 110 watt SHO bulb uses 110 watts in 10" or even less if mounted in a pendant.
Another aspect of watts is the output of lumens per watts actually used. The output of a 400 watt incandescent bulb is about 25 watts of light, a 400 watt metal halide bulb emits about 140 watts of light. If PAR is considered to correspond more or less to the visible region, then a 400 watt metal halide lamp provides about 140 watts of PAR. A 400 watt HPS lamps has less PAR, typically 120 to 128 watts, but because the light is yellow it is rated at higher lumens (for the human eye). "
http://www.americanaquariumproducts.com/Aquarium_Lighting.html
