A control system for an aquarium lighting system in which motor drivers alter over time the relative inclination of a light source with respect to an ornamental feature (18) within the aquarium. The effect is that light intensity (92, 94) falling incident on an ornamental feature more accurately simulates natural light impinging on a natural environment from day and seasonal movements of the sun. In addition to the relative change in inclination, power settings for the light source can be adjusted to further mimic the effects experienced with daily variations of climate and/or weather. The system effectively changes the angle of incidence of light and outwardly facing areas of ornamental features or areas beneath overhangs receive programmable levels of illumination that would otherwise not be possible with an overhead, single fixed-position light source.
