Start with a small number of fish. Goldfish are the easiest fish for beginners. Some other freshwater fish you might like include guppies, medakas, swordtails or Siamese fighting fish. When you choose your fish, they should be active, lively and well fed.
A rectangular aquarium is ideal for your new fish. A fishbowl has a narrow opening which does not allow the water to contact air as easily. There should be 50 square inches of of water surface per fish. A 50 Sqare inch area would be 10 inches by 5 inches. The aquarium should hold a gallon per inch in length of your fish. So, if you have 3 fish that are 2 inches long each, then you need at least 6 gallons in your tank and the opening should be 150 square inches. Make sure you keep your fish aquarium on a level surface. Many people choose to buy a stand that displays the fish in an attractive way.
Your fish tank or aquarium should have a clear glass or plastic covering on top which keeps the dust and dirt out of the water and prevents evaporation, which is especially important in dry climates. More importantly, the cover helps to maintain the water temperature. Sudden changes in water temperature can kill freshwater fish. Gold fish thrive in cold water but if you have tropical fish you may need to keep your fish in 70-80 degree F water temperatures. Talk to the folks at your local fish supply or pet supply store to find out what species you can keep together and what temperature you should keep the water at. You will need a thermometer for your aquarium and if you keep tropical fish you will need an aquarium heater also.
Plants are important for removing nitrates from the water. Plants also absorb carbon dioxide and give off oxygen during the day. Although at night the plants will use up dissolved oxygen so you will need to install an air pump and filter to ensure the water is properly oxygenated at all times.
Soak plants 15 minutes in a solution of 3 tablespoons salt per gallon of water to remove any parasites. Rinse plants and embed in sand or gravel.
Prepare your aquarium the day before you get your fish. Wash out the tank with clear water and cover the bottom in 1-3 inches of washed gravel or aquarium sand. Set the gravel so that it is slightly higher on the sides and more shallow in the center. This will trap dirt and make cleaning easier. Fill your tank with water being careful not to uproot plants if you have them. Let the aquarium stand uncovered for 24 hours. When you add the fish float them in their transporting bags in the tank for about 10 minutes so they gradually acclimate to the new water temperature. Keep a close eye on the time or set a timer. You do not want to leave your fish in the bag for longer than 45 minutes.
To maintain your freshwater fish aquarium, keep it out of direct sunlight but in a place where it will receive regular light. Direct sunlight can cause overheating or increased algae growth. You can opt to install a florescent light on the top of your tank to ensure the tank has the correct amount of light without adding extra heat.
To clean your tank, scrap algae from the sides with a scraper. Use a dip tube to remove algae, sediment and uneaten food. You can get these tools from your pet shop. Trim plants occasionally.
Feed your fish twice a day at the same time if possible. Fish can go without food for up to 2 days so weekend trips are okay but if you vacation any longer you will have to have a friend stop by to feed your fish. Keep a box of baby cereal on hand in case you run out of fish food. Don’t overfeed your fish. Only feed them what they can eat in 10 minutes. Any more will pollute the water! Remember that fish breathe water so keep it clean.
Problems and illness in fish can sometimes be spotted and remedied. If you notice your fish are gasping for air at the top of the tank, this means there is not enough oxygen in the water or the fish are overcrowded. Or it can be too dirty or too hot. Address each possibility and improve the conditions.
Have a second tank available in case any fish become sick. If you notice a sick fish, separate the fish into its own tank to avoid spreading illness to other fish. If a fish is pulling a string of feces behind the fish can be constipated. Give the fish greens.
A slimy white coating indicates fungus. You can try putting the fish in a separate tank with 3 teaspoons of salt per gallon of water. If there is no improvement, seek the advise of a fish specialist.