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Salt water aquarium lights


Light is one of the primary factors for life on our planet. When our planet was born and there were oceans on the surface, almost immediately life started on our planet. The main factor was the water as the environment and the sun being the source of energy. In salt water aquariums you have to appreciate this fact. All creatures (with the exception of fungus), need light.

I should probably start with the impacts of light on the living organisms within your tank. If you want to have anemones and green salt water plants, you have to know one thing; They will grow to the places where the light is. So if you choose a place for the aquarium which has a plenty of light from the outside of the tank, they will not grow as usual, but towards the aquarium glass and such situation may affect the look of the tank. This natural light can affect the tropical fishes too. Some are photosensitive and they are accustomed to feeling sunlight on their backs, because in normal condition the brighter light comes from the surface. However, if the light is brightest from the side, they will be disorientated and tend to swim sideways. The main thing is to choose a good position for the tank. It should be in the darkest area of the room where there is no direct sunlight throughout the day. It is essential that the temperature is stable, so do not choose a place near doors or openings. Another very important factor is that fish need to have a "night and day" period. Some fish will eat through the day, some only at night, some even before sunset or sunrise. This is the same with breeding and mating. Some species breed only during nights and some only during daytime.

Algae and light

Another good result for correct lighting is algae. It is the food for many salt water aquarium fish, so there should be ample algae in the tank, especially if you want to raise algae-eaters. Most algae-eaters are omnivore and salt water algae is very important green food for them, which they can eat between feeding times. This ensures that the fish will spend their time doing something more creative than just swimming around and doing nothing. Salt water algae requires a lot of aquarium light for growth. Light enables one special process in the bodies of plants — photosynthesis. It is a process whereby water and carbon dioxide convert themselves into oxygen and glucose, which is the building material for algae and plants. This glucose is the reason why fish and other aquarium creatures eat algae. Glucose is energy which keeps the green eating organism alive. You can also say that you don’t want any salt water algae in the tank because it looks ugly, but you have to think about what is more important: your fish’ health or the look of the tank. You can choose fish which do not eat algae. Some algae will not grow quickly and often the fish will eat it before it becomes unsightly. Another important role of the algae and green plants is that they create oxygen and process the fish excrement, keeping the NO3 level low and making the water safe and "natural" for the fish. You have to be careful with the aerator. Do not shut it down through the night, because plants breath oxygen at night. This would result in the fish not having enough air and can be fatal.

Not only are fish and plants affected by the light, but also micro-organisms. They are also an important part of the fishes’ feeding habits. They play an important role in the water chemistry balance. Some of them can produce many toxic wastes, especially those anaerobic, which reproduce at dark. So if you don’t have salt water aquarium lights in the tank, these micro-organisms can produce so many toxic wastes that your fish will become ill and die.

There is another role of salt water aquarium lighting. You want to see your fish so that you can see how they feel, if they are sick and if they are eating and so on. The process of choosing the light is important due to the fact that various fish will look different, under different lighting conditions. It depends on what colour light is emitted by the bulbs. The light should be turned on for about 12 hours a day. In tropical salt water aquariums it can be more, but in cold water aquariums it should be less and in such tanks you also should simulate seasons of the year. In the summer season you should provide more light than in the winter season. Another important aspect is that shutting down the light instantly, is not a good idea. The fish can be scared and can injure themselves. You should gradually turn down the light in the nighttime and there should be similar mechanism for mornings too. This is a good choice if you have fish which eat or breed during sunset or sunrise. You can turn the aquarium lights off in the tank and after a few minutes, shut down the light in the room. Another option is to use blue light tubes throughout the night. They require only a couple of watts and have intensive dark blue light, which is just sufficient to see the fish in the tank. This blue light simulates the moon shine and it is recommended for growth of corals.

Choosing the light for your marine aquarium

When you are choosing salt water aquarium lights, you have to make a compromise between what you want and what your fish need. Fish live in different depths of the sea and in different depths, the light varies. Also tropical salt water fish will need more light than fish from the colder regions, because in the warm waters there is more light, except of course the fish and creatures which live in rocks and caves. Don’t forget that you should keep fish only from one region, so you can provide the best conditions for all of the fish. You should bear in mind that more light you have in the tank, the greater the amount of algae. If you want to have only a small amount of light, you should choose appropriately, e.g. one fluorescent tube. For more light you should have more of them, because the strength of one fluorescent tube is limited. And how can you know how much light you should have in the aquarium? You definitely need hiding places. If the fish are constantly in the caves, you have too much light in the tank. You should start with proportion one watt to one litre of the water. Then you watch how your fish react and how you like the lighting in the tank. It the fish seem OK, but you would like more light, increase the lighting a bit.

The ordinary light bulb is not a good choice for any salt water tank. It is not effective because most of the energy transforms into heat and the heat may overheat the tank and cause a temperature imbalance.. I don’t even have to mention that you will have to use an aquarium chiller and it will expend even more energy during the warm periods of the year. That is why low temperature fluorescent tubes are the best choice, even if ordinary light bulbs are cheaper. Another advantage of fluorescent tubes is, that they last longer and are safer. An ordinary bulb may explode and the glass pieces can hurt the fish. You can choose from many variations of the tubes. You may choose tube with long or short wavelengths. Long waved are red-orange and short waved are blue, violet and indigo. You should not use normal tubes which you have in you room as a light. You should buy these products from aquatic shops only, or specialised pet shops, because only those tubes can provide a light that is suitable for plants and fish. Ordinary light tubes which you use in the room give only white light and it does not simulate the sunshine as good as those special tubes. It is a fact that the tubes are not as bright as ordinary bulbs, but most aquarium hoods have place for more tubes. Especially those which you buy with the aquarium. Usually the bigger the tank is, the more place for tubes. You can also use aquarium spotlights if you wish. They can be special spotlights which hang above the tank. These are very effective because the aquarium light does not come in contact with the salt water. This is good because the water will rust the light if it is not waterproof. If you use hood it also has to be waterproof, or you can use a glass under the light. The spotlights can have a very intensive light so they are suitable for deep marine tanks, however you should be careful when you are using such strong light. Very strong salt water aquarium lighting may harm some fish, especially those which like shadows . Strong lighting can warm up the water and can cause instability of the temperature. Remember that the warmer the water is, the less oxygen there is, so you also will need a strong aerator.

The position

You should choose the position of where the marine aquarium light should be. The position of the light is very important. The best position for a bulb is in the front of the tank, but understand that this will cause algae growth and may inhibit your view into the tank. Unless of course you want to see how are your fish eat the salt water algae. Then you can install the light on the sides of the tank, or at the back of the aquarium. This position will not provide enough light for a good view, but the algae will not grow on the front glass and fish will have enough light too. It is a good compromise. The best position for the salt water aquarium light in a tank with salt water algae-eaters is above the salt water decoration and rocks, so the algae will grow on them. Especially if you have larger rocks in a reef style, where the largest stones are in the back and the smallest are in the front. In this case, you should probably mount the lighting directly above the rocks.
Document modified on Sat May 21 9:29:46 UTC 2011
Document created on Thu Feb 7 19:13:13 UTC 2008
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