How to Cycle an African Cichlid Aquarium

A new aquarium's water chemistry must be stable before you can safely add a full tank of fish. During the initial 8 weeks, fish waste, food and bacteria interact, causing toxic ammonia, nitrite and nitrate to develop as part of the natural nitrogen cycle. A mature filter and its good bacteria neutralize waste efficiently, but a new setup needs time to allow a bacterial colony to grow, and too many fish in an immature tank overwhelms its biological capabilities. Introduce fish gradually, one or two at a time, after the first couple of months. You can cycle your African cichlid aquarium with or without fish to complete the nitrogen cycle and stabilize the tank.

Things You'll Need

  • Fish
  • Fish food
  • Aquarium ammonia test kit
  • Aquarium nitrite test kit
  • Aquarium nitrate test kit
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Instructions

  1. Cycling With Fish

    • 1

      Set up your African cichlid aquarium and purchase one or two fish to begin the cycling process. Pseudotropheus zebra are a hardy species and a good choice of starter fish. An uncycled aquarium needs bacteria and waste products to kick-start the nitrogen cycle and naturally robust fish stand a better chance of surviving the less-than-perfect water conditions.

    • 2

      Feed the fish daily and change approximately 15 percent of the water every day for the first week. Don't remove debris from the gravel as it encourages healthy bacteria to populate the substrate in the long term.

    • 3

      Check the water for toxins after 1 week, using the test kits. There will be high levels of ammonia at this point in the cycle and trace amounts of nitrite as the decomposing waste in the water is broken down by bad bacteria. The byproduct of this process is ammonia, and until the filter is established, good bacteria cannot intervene and make the water safe.

    • 4

      Monitor ammonia, nitrite and nitrate levels each day and continue to change 15 percent of the water every couple of days to keep toxins within the acceptable ranges indicated on the water test kit charts. If levels spike suddenly, replace half of the tank water immediately. Ammonia should dissipate completely within 2 weeks, followed by nitrite and nitrate as the healthy bacteria colonizes the filter and substrate, outnumbering the bad bacteria.

    • 5

      Add more fish when toxins drop to zero. A tank normally takes around 6 to 8 weeks to complete the nitrogen cycle. Introduce one or two fish each week and continue to check for raised ammonia, nitrite and nitrate once a week during the first 6 months.

    Fishless Cycling

    • 6

      Set up your African cichlid tank with the appropriate water temperature and lighting conditions. Do not add fish at this stage.

    • 7

      Sprinkle a pinch of fish food into the water every day. The food will decompose, produce ammonia and start the nitrogen cycle.

    • 8

      Change some of the tank water only if it gives off an unpleasant smell or looks dirty. There are no fish, so water quality is not too important in the early stages. The biological filter will ultimately take care of the water chemistry once a healthy bacterial colony is established.

    • 9

      Monitor ammonia, nitrite and nitrate levels after 1 week using water test kits. Fishless cycling follows the same pattern as cycling with fish. Ammonia spikes between the first and second week, before a build-up of nitrite and finally nitrate. The water is safe when the chemicals dissipate.

    • 10

      Add fish when toxins stabilize at zero. The nitrogen cycle usually completes in 6 to 8 weeks with fishless cycling, but ammonia may briefly spike again when you introduce fish after using this method. Only introduce one or two African cichlids a week and continue to check for ammonia a couple of days after each batch.