Well, for the folks with large aquariums, you need as many watts of LED to cover the area as you would with a single metal halide and decent reflector. For example, I have a 5ft x 5ft x 30in cube tank that is lit with only 4 250 watt metal halides. It would take at least this many watts with the current "state of the art, high end, professional" LED fixtures at a price of about $4000.00-5000.00. Even with yearly bulb costs of about $250 for this tank, it would take about 20 years before the LED paid for itself, assuming the fixtures last that long which we know they probably won't. So, since there is still high demand for metal halides, with us and the folks growing plants, I doubt we see their demise any time soon.