10 Points Best Answer?

The watts per gallon is just a general guide. The general opinion among reefers is this: T5s are better than PCs, Halides are better than T5s. I myself run a T5 system over my nano reef. Lighting is important, however, other additives are important too. Calcium and magnesium make a big difference and can make up for lower wattage. Check out reef forums for more opinions, it is a well discussed topic, and education in this area is on going, no matter your experience.