FIG. 5 represents 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 therefore eliminates areas in an aquarium that could otherwise be saturated with excessive light (which could also promote unwanted algae growth) from a single fixed-position overhead light source, which saturation occurs as a requirement for light from that single fixed-position light source to penetrate downwardly into the depths of the aquarium. By providing a system that effectively changes the angle of incidence of light, 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.
