I need advise for lighting and placement for a saltwater fish/coral tank

Question

I am needing help/advise for lighting a 90gallon reef 4ft in length 22in in depth approx. metal halide not an option. currently using actinic and marine glo. specific quest: How many flor. bulbs needed; wattage; space placement from top of tank. # of hours turned on daily. I would really love to be able to set in up correctly. S I am reaching out to all you seasoned "reef builders"!!

Thank you sooooo much guys!!

Answer 1

The lighting you choose for your saltwater tank will depend on whether your tank will contain only fish or be a mini-reef tank. Fish-only tanks require no special lighting other than that which will allow for the most optimal viewing of these beautiful creatures. A standard pair of normal output fluorescent lamps should do the trick, with the amount of wattage to be determined by the size of the tank.

Lighting plays a very important and complex role in a mini-reef aquarium. Many marine organisms generally included in such a setup would not survive without lighting of the proper intensity and spectrum, so you will need to provide artificial lighting that imitates natural lighting as closely as possible. As with heating, you will want your lighting system to produce a minimum of 3 to 5 watts per gallon of water.

Fluorescent fixtures and metal halide lamps are light sources commonly used in mini-reef aquariums. Fluorescent lighting is usually more convenient, less expensive to purchase and to operate, and outputs less heat while running. On the other hand, fluorescent tubes can really only be used in shallow tanks (20 inches high or less) because they don’t penetrate the water very deeply.

Metal halides produce an intense light that penetrates much deeper than the lighting produced by fluorescent tubes. However, metal halides get exceptionally hot, which means a tank with this source of lighting will also require a cooling fan to maintain the correct water temperature. Metal halides are also more expensive than fluorescents to purchase and to operate.

For most fish-only aquariums, six to eight hours of light a day is ample. This amount of lighting will give the fish a predictable night and day cycle and allow them to feed by light. Keeping the amount of hours to a minimum will help to save on your energy costs and keep the algae in the tank at bay.

A mini-reef aquarium should be lit for about 10 to 12 hours every day. This schedule can be tweaked according to the way the organisms in the tank respond. Some may require slightly more or less light.