11.04.2016 Where the sun goes up and down The correct lighting allows aquarists creating appropriate and natural light conditions. Photo: © sera Natural living conditions are essential in an aquarium, because they help avoid care problems. Like us humans, fish also require a day and night rhythm. The correct lighting allows aquarist to ensure appropriate and natural light conditions. The light is essential in an aquarium: On the one hand it effectively presents the fantastic color variety of the underwater flora and fauna. On the other hand, light is a basic precondition for healthy fish and strong plant growth. Simulating the natural day and night rhythm is a key feature. Well balanced light and darkness phases are important to make the animals feel as in their preferred living environment. Diurnal fish need the dark time for recovery. Nocturnal species, however, sleep during the day and only become active when it is dark. Simulating daytimes in an aquarium The optimal lighting rhythm depends on the aquarium inhabitants and the plants. Too long light phases might, for instance, lead to excess algae growth. Sudden changes of light conditions should also be avoided. As in nature, a smooth change from entire darkness to bright daylight, and vice versa, is recommended. Aquarist can achieve this effect by using special dimmers. The sera LED Digital Dimmer, for instance, combines a dimmer and a timer in one device. It allows adjusting the light intensity of the aquarium lighting individually to the requirements of the fish. Combination with then „sunrise“ versions of the long-lived sera LED X-Change Tubes allows imitating atmospheric sunrises and sunsets. Due to the convenient timer function, the sera Digital Dimmer automatically and slowly increases and lowers the light intensity. Fish and plants thus have optimal light conditions 24 hours a day.