Aquarium Lighting

Fluorescent tubes are widely used for lighting. Mercury vapor lamps, also called HQL lamps, are no longer distributed, as metal halide lamps, also called HQI-Brenner, offer the same performance at a higher luminous efficiency. HQI-burners are required for tanks over 50 cm in height. This is because light intensity decreases rapidly with increasing depth.

These latter two exude a special charm by their point-like, light-emitting lamps (other than a long fluorescent tube). A particular result is greater surface movement of water into so-called sunshine kringle effects, as we know them from diving.

Fluorescents specially adapted for aquatics enable the simulation of various lighting conditions (for example, natural light, tropical sun, and a higher proportion of blue light to simulate a sea water depth). The selection of the lighting spectrum influences both the growth of aquatic plants (desired) and algae (usually undesirable).

Tubes with increased red and blue components are specifically used to increase the visibility of red, orange and blue colors of fish and corals, but also promote the growth of algae. They are most frequently used with full-spectrum lighting, which create coloring like the sunlight.

The use of electronic lighting controls allows the timed production of different lighting moods (color, brightness) and simulation of sunrise and sunsets. In most cases, the control of lighting via a simple timer is sufficient. If tropical fish are kept, the duration should be based on twelve hours.

The aquarium lighting is often integrated into the aquarium cover. You must avoid the prevailing humid conditions and eliminate the risk of electric shock when working at the aquarium! In any case, to avoid unnecessary and significant energy losses due to evaporation, an aquarium cover should be used.

From an aesthetic point of view, but also to observe the behavior of nocturnal animals, moonlight lighting is becoming more popular. This lighting simulates a faint bluish moonlight after the main lighting is switched off. These lighting effects are realized with low power LEDs or cold cathode tubes.

The effect on the nocturnal habits of the fish is controversial. On the one hand, an absolute darkness is unnatural and can cause stress in animals, but on the other hand the “moonlight” is too bright and prevents the animals from resting. There are isolated reports of improved spawning behavior under moonlight lighting. Meanwhile, T5 and T8 fluorescent tubes can be a good replacement for the LED tubes.

Aquatic plants need photosynthesis, and although the entire light spectrum is required, they preferably utilize the red (around 700 nm) and to a lesser extent the blue (450 nm) spectral range. White LEDs emit in this spectral range. By using LED tubes, lighting energy demand can be cut by about 30% compared to the fluorescent tube