I also got an aqueon 55 gallon tank
I got the MarineLand double bright LED lights as I also thought there wasn't enough light in the tank with the flourescents. I got 2 of the 18-24" lights and they fit perfectly. You would get more light with buying one 48" light. I like the light as it creates areas of light and shadow in the tank. There is also a shimmering effect from these on the water moving from the filters. I also went with 2 hagen filters instead of the one that came with the tank. The plants are thriving. I have the lights on a timer for 15 hours per day.