How to Set Up a Brackish Water Fish Tank

Brackish water occurs where rivers meet oceans. In a brackish environment, the water measures a lower salinity than seawater, such as an estuary, a mangrove swamp or a salt pond. Many interesting creatures inhabit brackish ecosystems, and juveniles of many marine animals use brackish environments as nurseries. Only an aquarist who has mastered freshwater fish tanks should attempt a brackish aquarium. Brackish aquariums require more care than a freshwater tank, but less than a reef aquarium.

Things You'll Need

  • Fish tank
  • Mechanical Filter
  • Heater-chiller
  • Sand or mud
  • Rocks and driftwood
  • Marine salt
  • Refractometer
  • Brackish animals
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Instructions

    • 1

      Choose the exact environment you wish to replicate: a mangrove swamp, a salt pond, an estuary near a river, or an estuary near an ocean.

    • 2

      Set up a fish tank, mechanical filter and heater or chiller. Badman's Tropical Fish suggests that a mangrove swamp or salt pond aquarium requires slower-moving water than an aquarium designed to resemble the river-end of an estuary, where the water flows much faster.

    • 3

      Add a substrate of sand or mud, and then add rocks and driftwood. Get everything placed exactly where you want it. Estuary fish need more open water, while mangrove and salt pond fish like plenty of hiding spots.

    • 4

      Add marine salt. Using a refractometer, establish a specific gravity between 1.005 and 1.020, depending on the species you will keep and the ecosystem you choose to replicate.

    • 5

      Cycle your aquarium. This means running the tank for at least two weeks without any animals to allow beneficial bacteria to build up in your filter media and your substrate. Otherwise, any animal you add to your tank will die from ammonia poisoning.

    • 6

      Establish a healthy pH, using chemical additives if necessary, and establish water temperature depending on the species you wish to house in your brackish fish tank. Generally, brackish fish require a pH between 8.0 and 8.4 and a temperature between 80 and 84 degrees Fahrenheit.

    • 7

      Slowly add animals, starting with a few crabs or snails, adding two to three more animals each week. A general rule of thumb says to keep no more than one inch of animal for every five gallons of water in your aquarium.