When planning the purchase of a new aquarium, it is important to consider several things ranging from the type of fish and inhabitants to ease of maintenance, cost, size, type of aquarium and esthetic value.
It is common for people to buy a fairly small aquarium as their first because it is less intimidating, and less costly. It is easier to clean and reach into, but some experienced aquarists believe small aquariums are more difficult to keep the rather fragile eco system balanced. The larger the aquarium, the more time it takes for sudden changes in water chemistry, temperature or other factors that affect the health of the fish and other inhabitants to have affect. The most common mistake people make is putting too many fish in the aquarium or putting in fish that if healthy will quickly out grow the aquarium. It is therefore important to choose the right fish in relation to the size of the aquarium and keep the number within reason.
For aquariums ten gallon or smaller, fish that are under two inches at adult size are the most appropriate. Some fish of this size are schooling fish and quite active and require more room. Fish like guppies, platties, mollies, Endlers and the like are appropriate. Freshwater shrimp are wonderful foragers and full of playful antics. Otocinclus catfish and dwarf Corydoras catfish species are also suitable. Medium size aquariums from 20 to 40 gallons generally house fish up to four inches in size comfortably while 55 gallon to 100 gallon may accommodate fish up to eight inches. When mixing species together, make sure they are compatible.
Aquariums come in all shapes and sizes. Some are made strictly for esthetic reasons: to look like furniture or actually built into furniture, hanging on walls like a picture, or very ornate. These type of aquariums may or may not be designed with the ultimate health and well being of the fish and animals in mind. Take a close look at these and ask yourself if they provide enough room for the fish, enable proper filtration, and easy access to water changes and other required maintenance. Having a coffee table aquarium with dead fish in it is not particularly attractive.