One of the areas in which technological development has really made a huge difference to the health and longevity of reef tank setups is lighting. Until a few years ago, the aspiring reefkeeper was faced with a choice of either expensive metal halide lamps (needing supplemental blue lighting from fluorescent tubes), a combination of fluorescent tubes (that even the experts couldn’t agree on), or mercury vapor lights that were completely unsuitable in terms of color spectrum.
Those days were over with the arrival of specialized fluorescent tubes designed for marine systems. Subsequently, quite a range of such tubes has come on the market, considerably simplifying things for those of use with reef aquaria. Metal halide lighting has also evolved. Bulbs are now available which deliver the correct spectrum for invertebrates without the need for supplementary fluorescent tubes. Prices have also become more affordable.
Marine aquariums need light for a number of reasons. In a fish-only system the primary reason for lighting the tank is to view the fish. If lighting of sufficient intensity is provided, macroalgae or even filamentous algae can be stimulated to grow, with the benefit of improving water quality. Algal growth also stimulates the establishment of populations of small crustaceans, providing both a direct (the algae itself) and indirect source of food for the fish.
In a reef tank, lighting is much more important because most of the corals and invertebrates depend upon light as a primary source of food. Within their tissues, these animals harbor populations of single celled algae, known as zooxanthellae, which photosynthesize to produce nutrients then used by the host.
In nature, reef inhabitants reside a different depths, therefore requiring different intensity of light to thrive. Red light penetrates water poorly, whereas blue, violet and ultraviolet light can reach much greater depths. Consequently, in order to choose the correct spectrum lighting it’s important to know where on the reef your pets came from. If you have any questions, please come in or give us a call.