.. in the same way that the ammonia is removed (Madison 42).
This second form of bacteria will consume the nitrites as food, and expel nitrates back into the tank. The last step of the nitrogen cycle is to rid the aquarium of nitrates. Although fish and invertebrates can stand a higher level of this chemical, it is something the hobbyist must watch closely. There are bacteria that will consume the nitrates, but at a much slower rate than ammonia or nitrites are consumed (Madison 42). This allows some forms of algae to feed on the remaining nitrates. Although some algae growth in a marine aquarium is beneficial, an algae bloom can occur if nitrate levels grow too high.
The best way to control nitrates within a marine aquarium is by doing partial water changes on a regular basis (Paletta 3). Replacing 10% to 20% of the water every month is an ideal way to keep nitrate levels low (Paletta 3). This also will eliminate other harmful chemicals from building up, such as phosphates. Phosphates within the tank can quickly cause algae to grow over everything within the tank.
The hobbyist can had certain chemicals to rid the aquarium of the harmful chemicals, but experience has shown that the added chemicals can cause harm for certain tank inhabitants (Walker). Although these are the main chemicals the hobbyist must watch out for to keep from killing the tank inhabitants, there is one other chemical that requires a constant watch. To promote healthy growth, calcium levels in the water must also be watched. Calcium is primarily a self-replenishing chemical; the rocks and sand in the aquarium contain calcium, and as this material slowly dissolves the level of calcium will be maintained.
However, in aquariums containing high amounts of live corals, the calcium may be depleted faster than it can be replenished (Goldstein 21). In these cases, the hobbyist must add calcium supplements to his or her aquarium. “Apart from good water conditions, the single most important factor in the success of any aquarium containing photosynthetic organisms is the quantity and quality of the light provided” (Tullock 105). There are a variety of options for the hobbyist to consider when it comes to lighting his or her tank. At first this might appear to be an easy subject. Put the aquarium under a window so it will receive natural sunlight, or place a few light bulbs from a hardware store over the top of the tank.
Both methods would be a drastic mistake. First, direct sunlight would cause a tremendous growth of algae, much like algae will grow in a pool or pond. Secondly, normal light bulbs put out a frequency of light that is suited for human eyes but lack most of the light spectrum that is required for coral growth. A tank lit in this manner would quickly kill off most of the corals and invertebrates that are popular in the marine aquarium (Larson). What the hobbyist needs for his or her aquarium is specialized lighting. Lights that provide the correct spectrum and most closely resemble direct sunlight are best for most aquarium inhabitants.
How large the tank is and what inhabitants are residing in the tank will determine how much lighting is required. The ideal setup would provide an equal amount of light, and a spectrum of light that resembles direct sunlight (Gamble). Since this would be extremely expensive and difficult to achieve, an easier way to determine the amount of light needed is to have four to eight watts of light for every gallon of water in the tank (Larson). For example, a 75 gallon aquarium should have from 300 to 750 watts of light. There are four main lighting options that will fill these needs.
All of the options include some form of florescent lamps, and can be mixed to provide optimum lighting conditions to any aquarium. The first option is to stick with the lighting that comes with a newly purchased aquarium. These lights, referred to as Normal Output (NO) bulbs, are very low power, only providing 15 to 20 watts of light per bulb. These bulbs are also the cheapest option of providing light to the aquarium (Reefkeeper’s FAQ). Because of the low output of these bulbs, they are a poor option for lighting a marine aquarium.
The next option for the hobbyist is High Output (HO) lights. This type of lighting is identical to NO lights except they provide a higher output of light, normally 50 to 75 watts per lamp (Reefkeeper’s FAQ). However, because these lamps still provide a low output of light they are best suited as supplemental lighting to the aquarium. The most common lighting for a marine aquarium is Very High Output (VHO) lamps. These lamps provide from 75 to 110 watts of light per bulb, and when used in quantity they can easily provide enough light to satisfy the needs of any inhabitants (Reefkeeper’s FAQ).
Yet to provide enough light for an average sized aquarium, at least four of these bulbs would be needed. Therefore, this form of lighting can be extremely expensive and create an abundance of heat that needs to be dissipated. The last option, and probably the best option for lighting are Metal Halide (MH) lights. This form of lighting is also florescent, but it is shaped more like a standard light bulb. Although expensive, these bulbs can provide a much higher output, from 150 to 400 watts per lamp (Reefkeeper’s FAQ). Even though these lamps are expensive, the cost per watt of light is actually less; since only one or two bulbs are needed for an average size aquarium.
Once the aquarium is lit properly and the hobbyist has the water quality he or she needs, fish and other animals can be added. Yet, the hobbyist is not done with either water checks or the lighting. Both are something that will require a constant watch. Each time a new fish or invertebrate is added to or removed from the tank the chemical balance of the water is upset. The bacteria within the tank will then have to readjust either by reproducing more or dieing off.
In either case, the ammonia levels will temporarily rise until the chemical balance of the water settles back down. This requires the hobbyist to consistently monitor the water. If he or she does not, the quality of the water may quickly become uninhabitable. Lighting also requires constant watch. As the bulbs age, the output power and light spectrum will change.
Most florescent bulbs will last around 18 to 24 months (Reefkeeper’s FAQ). To keep good lighting conditions within the tank, good rule of thumb is to replace the bulbs within the tank every year. With properly maintained water and lighting, the marine aquarium can become a showpiece in any home. What appears to be a lot of work monitoring water conditions and lighting quickly becomes only a minor chore as the aquarium begins to regulate itself. Considering the amount of work and money a fireplace requires, the aquarium is a much easier and cheaper centerpiece that can be added to any room.
It becomes a landscaping of art that even the best painters have difficulty capturing, and can be enjoyed by everyone. Animal Science.
