Optics are a force multiplier...Hate to talk military but very true...
The Naked Cree LED has a spread of about 180 degrees.
Some optics are only 60-70% efficient. Others are close to 90%
Much light is simply wasted. By optimizing your optics you can double the light by focusing it precisely were your corals need it or you can spread it and minimize the spill.
For my setup 60 degree Carclo optics work quite well. I'm thinking about changing out the front bank to 30 degree to minimize the spill on the glass.
If I had lees room I would look at some of the higher quality reflectors.
Having a tank this size has the draw back of you have to clean the glass/acrylic which is not fun...Reducing the light on the sides helps...