Types of Aquariums
People decide to keep aquariums for a wide variety of reasons, and it is important that you identify those that have compelled you to take up this hobby. If you simply want some beautiful fish to watch after a stressful day at work, you will approach the hobby with a different perspective than someone who wants to breed endangered species or whose main interest is in learning about the secret lives of aquatic invertebrates. Whatever your motivations, the enjoyment you find will no doubt encourage a greater appreciation of aquatic animals and the places they inhabit.
Marine habitats usually provide animals with environments of extremely stable conditions, in terms of temperature and water chemistry. Coral reef animals, for example, experience very little in the way of environmental changes. Therefore, these animals have not evolved mechanisms to cope with the often drastic fluctuations in water quality and water chemistry that may occur in the home aquarium. Fish and invertebrates from large rivers or lakes are similarly unsuited to coping with change. For this reason, such creatures may be extremely difficult to keep in captivity unless environmental stability can be guaranteed. Similarly, freshwater animals from unique, isolated habitats, such as caves, will not thrive unless their specific requirements are met in captivity.
Animals, both marine and freshwater, that thrive in unstable conditions in the wild are generally resilient creatures in captivity and make excellent first choices for the new hobbyist. In the ocean, such creatures would include those that are found in tidal pools, subjected as they are to daily changes in water depth, temperature, and oxygen levels.
Perhaps the hardiest of all aquarium candidates are freshwater animals that dwell in small freshwater ponds. Such animals have evolved unique methods of coping with the frequent fluctuations in temperature and water chemistry that occur regularly in their native habitats. Consider, for example, lungfish, which withstand drastic changes in water quality and can live under the mud for up to three years without food or water, breathing atmospheric oxygen only.
The incredible advances made recently in aquarium life-support systems, may, in some ways, hinder the new aquarist. With so much hightech equipment available at once, one may miss the basic steps in learning why certain techniques work and others do not. Read about the basics, and consider starting simple setups before attempting more complex aquariums.
You should also consider the time and expense that aquarium ownership and maintenance will entail. Complex setups generally require much time and maintenance, and marine aquariums will, in general, be more expensive to establish than freshwater tanks. However, remember that larger aquariums confer more stability upon the captive environment. Small changes in water chemistry and the like will be much more drastic in a 10-gallon aquarium as opposed to one that is 55 gallons. In most cases, it is wisest to start with the largest aquarium that you can afford and reasonably maintain. Marine animals are generally more sensitive to environmental changes than most freshwater species. Unless you are keeping only the hardiest of species, it is best to begin with a marine aquarium of at least 40 gallons in size.
The type of animals that interest you will also influence the time and expense that you will need to devote to your aquarium. Animals that need to consume a wide variety of tiny, living food items (like pipefish) are more difficult to maintain than are goldfish, which will thrive on a diet of commercially available flakes. Although a well-established community of animals and plants will actually lessen the hobbyist's work in the long run, the initial stages of establishing such systems will take more time and effort than will single-species tanks. Similarly, if you are seeking to keep invertebrates or to keep fish with invertebrates, you will need to spend a good deal of time in research and in observing your pets' interactions with each other.
It cannot be stressed enough that the hobby should be a source of enjoyment to you, and not a job. Keep this in mind when deciding how to approach aquarium keeping. A system that is manageable and pleasurable will enable you to learn and to share your observations with others. An aquarium that is beyond your means, in terms of expense and expertise, will be a source of frustration and will likely result in the loss of animals and in you abandoning the hobby.
How many fish can I keep in my aquarium?
The usual rule is that you should allow 4 gallons of water for each 1 inch of fish (excluding the tail). This rule is, however, is extremely general. The true answer will be determined by many factors, including fish species that you keep, tank design, and the nature of your life-support systems.
When considering shape, remember that a large water surface is helpful in allowing for the effective exchange of oxygen and carbon dioxide between the air and the aquarium. In practical terms, this means that long, low tanks will usually allow you to house more animals then will short, high tanks of the same volume. The wide variety of “designer” tanks that are now available can be extremely tempting, but they may not allow for the establishment of suitable environments for most animals. You might consider using such tanks for a particular individual animal or species that is amenable to the tank's shape. A high hexagonal tank, for example, might be planted with eelgrass and stocked with animals such as shrimp and seahorses, or those that will utilize the shape of the tank in their wanderings, such as snails or sea stars.
Aquariums are now available in either glass or acrylic. Each of these materials has its advantages and disadvantages. Glass is more likely to break than is acrylic, but it is far less likely to scratch. Acrylic generally provides superior light transmission, but it is usually more expensive than glass.
Those who keep marine aquariums are fortunate in that most of the associated life-support systems are now manufactured in corrosive proof materials. Saltwater spray is, however, extremely corrosive and seems to have a way of spreading from even the tiniest of openings in your aquarium's cover. In establishing a marine aquarium, use only equipment specifically designed for use with saltwater. Be sure that any supplies made of metal or other corrosive materials are kept well away from the aquarium. In the event that you must use metal or other such objects, be sure to paint them with three to four coats of polyurethane varnish and to seek the advice of an expert before attempting to waterproof.