First, let me predicate this with the statement that "not all LEDs are created equal". Which is to say 10 watts of one type of bulb is not the same as 10 watts of another type of bulb. Less expensive LEDs will be lucky to provide 70lumen of light per watt consumed, while CREE can exceed 120 lumen per watt.
So, keeping that in mind, a 4 ft 75 gal
tank would require 2 fixtures with 120 watts of CREE leds, or 240 Watts of LEDs, but might only be run at 60% intensity, or a total of 144watts. That could mean, in excess of 17,000 lumen of light.
You lights will be a total of 54 watts. Assuming they are not high quality LEDs, you could be even lower on your light. As such, I suspect those LEDs would only be good for polyps and 'shrooms