This information was pulled directly from the manufacturer's instructions:
The addition of a full spectrum light to the AquaFuge can provide excellent growing
conditions for photosynthetic invertebrates and various species of algae. The AquaFuge
has been specifically designed to accept some of the smaller sizes of compact fluorescent
lighting on top of the refugium. Caulerpa and other decorative algae may be grown out of the
reach of herbivorous fish. By having an area where algae can thrive, the competition for
nutrients can help to reduce the growth of nuisance algae in the main tank.