LED Reef Tank Lighting
I have a 29 gallon Oceanic Biocube that I am looking to have a custom LED setup made to light the saltwater reef. The tank originally comes with 2 power compact flourescent bulbs at 36 watts each. I would like a LED panel consisting of blue and white leds to simulate the daylight and actinic lighting of the flourescent bulbs. They make a Metal Halide HID light upgrade for the Biocube but I don't like the heat or power consumption of that type of lighting fixture. You can see how this company modifies the hood to fit in new lights which may give you an idea of how the LED panels could be custom made to fit. They put up to 150 watts of Metal Halide lighting so I need to try and fit as many LED's in the top hood as possible. I don't know what the lumen output of each LED would be but I would like to see if you can calculate the LED lumen output in comparison to 150watt Metal Halide bulb.
LED Efficiency and Reef Tank Lighting
A common myth in the world of LED lighting relates to the efficiency of the LEDs. When utilized properly LEDs can be extremely efficient, even more so than HID lighting, in some cases. The nature of the LEDs will allow the designer to preprogram the overall efficiency. In the majority of cases LEDs designers intentionally program their products the operate inefficiently. There is only one reason for this design choice. By engineering, an LED lighting product that operates less efficient. A designer is able to produce an equivalent amount of light while utilizing a greatly reduced number of total LEDs. Driving the LEDs at an increased drive current always results in lack of efficiency. This simple but effective loophole allows the designer to reduce the total LEDs count by as much as 50% or more. In many cases this approach is perfectly acceptable, but is obviously unacceptable in lighting applications highly dependent on energy efficiency. Please consider the following example. Reef tank number one contains an LED hood with 100 LEDs. The LEDs are driven at a relatively low current, only 150 milliamps. Each individual LED produces about 50 lumens of light. The total light output from this hood is about 5000 lm, with a total power dissipation of about 45 watts. This equal is an energy efficiency rating greater than 100 lm per watt. Now consider reef tank number two which only costs 50% of reef tank number one. It also contains half the number of LEDs. The designers have chosen to drive the LEDs harder in order to make up for lack of light. Therefore, the second LED hood will still produce 5000 lm. What the manufacturer has not revealed is the title heat dissipation from the LED hood. The inefficient LED fish tank light dissipates close to 100 watts of heat. So at 50 lm per watt the second device uses twice as much energy while producing the same amount of total light. Most consumers naturally assume that LED lighting is more efficient when compared to traditional lighting devices. In the previous example the second LED reef tank light was actually much less efficient when compared to a typical HID light source. In many common LED products today this is often the case.