Caring for freshwater fish includes having the right equipment, proper fish nutrition, and maintaining healthy water. Equipment includes the basics: a tank, filtration system, and a light source. Fish nutrition depends on the type of fish you have, but most freshwater fish have fairly simple nutritional needs. Proper water conditioning is vital for a successful freshwater aquarium.
You can choose either a glass or acrylic tank when caring for freshwater fish. Acrylic tanks come in more varieties of shapes than glass tanks, and are better insulators. An acrylic tank is also clearer, and allows in more light, than a glass tank. However, acrylic tanks are far more expensive than glass tanks, often two to three times the price. Acrylic is also very easily scratched, and you must be very careful when cleaning both the inside and outside of the tank.
Your filter system may be biological, mechanical, or chemical, or could employ a combination of these types. The most common filtration system for freshwater aquariums is an under gravel biological filter. Water is pulled either down through the gravel or (with a reverse flow filter) down from the top of the tank and then up through the gravel. The size of the filter you need when caring for freshwater fish will depend on the capacity of your tank.
When caring for freshwater fish in a tank with no live plants, a simple low-wattage fluorescent light is fine. If you have live plants, your lighting needs will be a little more specific, depending on the type of plants you have. You can usually expect to need 2-5 watts per gallon of tank capacity when dealing with live plants. Select a heater appropriate for the size of the tank, and invest in a quality thermometer to monitor the temperature. The correct temperature for the tank will depend on the fish living in it.
Fish nutrition is an important part of caring for freshwater fish. Fish food comes in a variety of forms. Common types include flakes, pellets, frozen food, and gelatin. Different fish require different foods, and may need to be fed on a different schedule. Always find out the individual nutrition needs of particular fish before adding them to your aquarium. Since you cannot generally segregate fish during feeding time, or keep most of them from eating whatever is put into the tank, it is important to keep species with similar fish nutrition needs.
Caring for freshwater fish includes making sure the water is safe for them. To ensure 
proper water quality, use a water conditioner to remove chlorine from the water. test the water for proper pH; the correct levels will depend on the species of fish you select. You also need to keep the water clean. cleaning your aquarium is something of a balancing act. You need to remove the “bad” dirt while still keeping plenty of the helpful bacteria that have built up in the tank. You also need to be sure to keep your fish safe and calm during the cleaning process.
Caring for freshwater fish has many important components. None of these are very difficult. It is simply a matter of having the right equipment and information to make caring for your freshwater fish fun and easy.
