Might not want to do that. Check for heat on that while your thinking about it. Electrical tape might have been a better idea. But, why not just buy more Blue LEDs and install them?
How easy would it be to add more leds and my tank is already really bright, mushrooms can't grow on bottom unless they are placed vertically. I have 16 led watts over a one foot, 8 gallon tank, about a 6 gallon display