This will be for a small tank, probably around 10 US gallons. I've used a 250 watt metal halide on one before, but don't want to go that route this time. The spectrum has to be simulated. At the depths that most corals live, seawater filters out nearly everything but blue and violet. It isn't possible to fully simulate the sun's intensity, even under meters of water, so people in the marine hobby use powerful low spectrum bulbs, typically around 6500K to 10,000K, and supplement them with lower intensity actinic bulbs in the 12,000K to 20,000K spectrum. My plan is to use these as the high intensity lighting and use CFL actinic bulbs to correct the spectrum. The result is remarkably close to the spectrum recorded at depth, just at a lower intensity.
The LED I have is a single LED chip with no power supply circuitry added.
LEDs are diodes and have a fixed forward voltage drop.
If you apply more voltage than that the diode will conduct as if it was a short circuit and an enormous current will flow, burning out the LED.
So you must limit the current, which can be done by a series resistor or by using a constant current PSU instead of a regular constant voltage PSU.
I get that. It seemed like you were insinuating that this would operate differently than a "normal" LED. I don't expect to just pump current into it. Still, I need a way to power it.