How to Care for Tropical Fish

Use a home water-quality test kit to measure the temperature, pH, dissolved oxygen content, ammonia levels, nitrate levels and salinity of water. Adjust these properties as needed.

Avoid adjusting water temperature abruptly. Tropical fish have narrow optimum temperature ranges and do not usually tolerate sudden changes in environment.

Regulate an airflow rate of 2 liters per hour, per liter of water. Control airflow with an aerator.

Provide a proper diet that has 30 to 36 percent protein, 10 percent fat and low amounts of carbohydrates. Be sure the fish food also contains required essential amino acids.

Feed your fish appropriate amounts based on the amount and type of fish in the aquarium. A general formula is to feed 10g flake food to 50 adult tropical or freshwater fish per month, but check with experts.

Avoid overfeeding, which results in poor water quality because of surplus food floating around in the tank.

Store food in moisture-resistant containers and place in a cool, dry area.

Keep food frozen for no longer than three months.

Equip aquariums with proper lighting to avoid heat accumulation and excess algae growth. Use a light recommended for aquarium use. Use dimmer devices to avoid startling fish when turning on lights.

Cover the aquarium to prevent contamination of water and to minimize temperature fluctuations.

Change 20 percent of the water every 30 days.