I don't think the watts per gallon rule is an exactly proportional number. On smaller tanks you need a certain amount of minimum wattage before your plants seem to do very well. I have 36 watts above my 2.5 gallon, which technically puts me at 14.4 watts/gallon. That would be WAAAAY to much on a large tank, but on my 2.5 it is about perfect. The reflector isn't the greatest and the lights overlap a bit.
I also have 2x24 watt lights in a canopy above my 5 gallon (9.6 w/g) and that also is just about right.
On larger tanks I generally only run about 3.5 to 4 watts per gallon.
OH! To get to the question of the tank, I have to say that it is already better than my first through about 5th try. The only constructive criticism I would give is that your java moss needs to be trimmed. It is sort of overwhelming the background plants. I would recommend you take the driftwood out before trimming so you don't end up with little bits of java moss all over your tank, like I have done in the past. It gets really hard to fish all those out.
Two 1 GA desktops, a 5 gallon, a 2.5 gallon, a 10 gallon, a 20 gallon, a 25 gallon, and two 75 gallon tanks, all planted.
I am an expert on algae, so ask me if you have questions. I know how to grow it, just not how to get rid of it.