I think I would try just 3 of those LED bulbs, running in a row down the middle of the tank, and about 6-7 inches apart. If that doesn't work, I would add a couple more in a second row, with the bulbs staggered between the other 3. This is just a guess though. I have 24 Cree LEDs, not quite as bright, 4 inches apart, used on a 30 inch long tank, about 24 inches above the substrate to get low light. A 10 gallon tank, with your LED bulbs mounted about 2 inches above the top of the tank would have the light about 10 inches closer to the substrate. You might get a spotlight effect with 3 bulbs, and you might get high light with 3 bulbs, but only testing would show for sure.