A freshwater aquarium is an aquarium that uses freshwater as its life source for the fish that inhabit it. The freshwater aquarium is, by far, the most popular type of aquarium for home hobbyists. They are easier to set up and maintain than saltwater aquariums and also somewhat less expensive.
The main components of a freshwater aquarium are the fish tank, pump and filtration system. While there may be size variations between pumps, a pet store will be able to recommend one for the size of fish tank you have. In most cases, the filter system may be an under-the-gravel system, or a power filter, which sits on the back of the aquarium. While all must be maintained and cleaned to some degree, when working properly, your freshwater aquarium will provide a suitable environment for many species of fish. It should be noted that tropical fish varieties may also require a water heater.
In addition to the cheaper cost of the freshwater aquarium, the fish put in it can also be very cheap. The cheapest is probably the common goldfish. Two or three goldfish can often be purchased for $1 US Dollar (USD). Of course, as with any hobby, it can also be as expensive as you would like. Some freshwater fish can be very expensive, the most exotic of which may be more than $100 USD. Generally speaking, the number of freshwater fish species available for a reasonable price, such as under $10 USD exceeds the number of saltwater species available in the same price range.
For those who wish to start with a freshwater aquarium, kits come in a number of different sizes and are available at many retailers. These will include everything one needs to get started with an aquarium hobby. There is also no concern about the pump when buying a kit, as it will be suited for the size of aquarium you have.
The freshwater aquarium comes in a number of different sizes as well. Some models only hold 1 US gallon (3.78 liters). Some home aquariums exceed 250 gallons (946 liters). Commercial models, which are often custom-made for a specific situation, can far exceed that.
It is important to remember that, although municipal water systems are freshwater, tap water cannot be introduced directly into a freshwater aquarium in most cases. Putting fish directly into an aquarium filled with city water will most likely result in their death. The water must be treated to remove chlorine and other impurities. Water conditioners can be purchased that do this nearly instantaneously.