How to Cycle a New Saltwater Tank With Fish

Saltwater aquariums can provide a beautiful and distinctive element to your decor, but they require knowledge and upkeep to thrive. When starting out a tank for the first time, you must cycle the tank in order to create a balance between beneficial bacteria and potentially harmful elements. It is possible to cycle the tank using hardy fish.

Things You'll Need

  • Aquarium tank
  • Salt water mix
  • Filtered water
  • Five gallon bucket
  • Ground coral or gravel for the tank bottom
  • Aquarium filter
  • Saltwater hydrometer
  • Aquarium thermometer
  • Water heater
  • Protein skimmer
  • Fish food
  • Tank decor
  • 1 to 2 starter fish, like Damsels or Clownfish
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Instructions

    • 1

      Rinse the tank with water and check for any leaks or damage. Attach your water filter, heater and protein skimmer to the tank, but do not plug them in. Rinse gravel thoroughly before adding to the bottom of the tank.

    • 2

      Mix the salt water mix with filtered water in the bucket. Once it is properly dissolved, use the hydrometer to ensure that the gravity reading is between 1.021 and 1.024. Add the water to the tank, and repeat until the tank is filled. Turn on the water filter and let it run for a day or two.

    • 3

      Set up lighting and any other aquarium accessories. Check to ensure that temperature is between 75 and 80 degrees Fahrenheit. Add one or two hardy fish, like damsels or clownfish, and leave the tank to cycle for approximately six weeks, checking nitrate and nitrite levels occasionally.

    • 4

      Test the tank to check for optimum conditions of zero ammonia and nitrite, and a nitrate reading of 20 ppm or less. If everything is ideal, add new fish over a period of a few weeks; adding fish too fast can upset the bacterial balance and ruin the tank. If your initial fish are too aggressive, bring them back to the pet store or give them to someone else starting a saltwater tank.