How to Keep Corydoras Catfish

Corydoras catfish (also called "corys" or "cory cats") are a tropical freshwater fish from South America. Like other catfish, they live at the bottom of the water column searching for scrap food among the substrate. Corys are a peaceful fish and are a great addition to community tanks such as aquariums without aggressive predators. They are omnivorous fish that will eat plant-based food and animals like bloodworms and brine shrimp. They are generally easy to care for and if kept healthy can live for 15 to 20 years.

Things You'll Need

  • Corydoras Catfish
  • Freshwater aquarium
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Instructions

    • 1

      Maintain a healthy water system and nitrogen cycle. The very first thing you should determine before you purchase any fish is to check the levels of ammonia, nitrite and nitrate in your aquarium water. Ammonia and nitrite should both be undetectable. Nitrates should be less than 15 parts per million (ppm) and, if you have a planted aquarium, should ideally be undetectable as well. If ammonia or nitrites are detected, let the aquarium continue to run for a few more weeks, then test again. If nitrates are high, change 20 percent of the aquarium water with fresh, dechlorinated tap water.

    • 2

      Properly acclimate your new cory. The best method is to place the cory in a clean bucket or bowl with the water from the store and add 1/2 cup of aquarium water every 10 to 15 minutes. Continue until you have added about 5 cups of aquarium water, then add the fish to the aquarium. This gives the cory time to adjust to the aquarium's temperature, pH and nitrate levels.

    • 3

      Maintain a stable pH between 5.8 and 7.0. The pH scale is logarithmic so changes in the numbers represent large swings in pH. Therefore, do your best to maintain a consistent pH in the aquarium. When you perform water changes, make sure the pH of the fresh water is the same as the pH of the aquarium. Sudden changes in pH can stress and kill the cory.

    • 4

      Maintain a temperature between 72 and 79 degrees Fahrenheit. Corys are tropical fish and need this warmer temperature to live. In warmer climates, leave the top of the aquarium open to allow air to flow past, cooling the water. In cooler climates, add an electric aquarium heater to warm the water.

    • 5

      Provide plenty of hiding places. Corys dwell on the bottom of the tank and will be frightened if left out in the open all the time. They prefer a tank with lots of live plants but you can provide artificial shelters as well.

    • 6

      Feed the corys an omnivorous diet. There are sinking pellet foods made specifically for catfish and these will provide a good diet for the corys. Also consider adding frozen bloodworms and brine shrimp.

    • 7

      Properly maintain your aquarium. This includes changing the water filter, using activated carbon and changing 10 to 20 percent of the water with fresh dechlorinated water every week.