DIY Reef Tank Lighting

To keep the organisms in your reef tank healthy, you want your tank lighting to mimic the natural light of your pets' habitat as closely as possible. This article will go over the different lighting fixtures and bulb choices so that you can decide what light will work best for your fish.

  1. The Basics

    • The first consideration when deciding on your lighting system is what type of organisms will need to survive under this light. If you plan to include photosynthetic corals in your aquarium, which in a reef tank you'll probably want, you will need to consider your lighting very carefully.

      The two things you should keep in mind when searching for the perfect lighting are wattage and the spectrum of the bulb.

    Wattage

    • Many reef tank hobbyists suggest a "watt per gallon" ratio to determine the best wattage for their tank. According to Reefkeeping magazine, a good ratio if your tank has mostly low-light coral is between four and six watts per gallon. If your tank contains light-loving coral, ten watts per gallon or more is suggested.

      However, you also need to take into account the depth of your tank when you calculate this. A tank that is three feet deep will need a higher-wattage bulb so that the light will reach all the way down to the bottom, whereas a tank that is only two feet deep won't need as much extra wattage.

    Light Spectrum

    • The light spectrum, also known as the Kelvin rating, of the lighting in your aquarium is the second aspect of a bulb you need to consider. Daylight spectrum bulbs have a Kelvin rating of around 5,000 K to 10,000 K, and they are ideal for freshwater aquariums. However, saltwater reef aquariums will need a higher Kelvin bulb, something between 7,000 K and 20,000 K to account for the higher density of the salt water, and to get enough light to the corals.

    Incandescent Versus Fluorescent

    • Finally, the last thing you should take into consideration when purchasing your lighting system is whether you want to use incandescent or fluorescent bulbs. Fluorescent are the most popular bulb in professional reef systems at the moment: they cost a little more to purchase, but since they use electricity more efficiently, they cost less to operate. Incandescent bulbs are cheaper to buy, but cost a little more to operate, because they tend to run hotter than fluorescents.