How to Start a Jack Dempsey Aquarium Tank

The Jack Dempsey is a medium sized cichlid native to Central America and parts of Southern Mexico. Named for the heavyweight boxing champion of the 1920's, Dempsey's have acquired a reputation for killing off other tank mates in droves. Setting up a suitable Jack Dempsey aquarium means keeping this fish's potential for aggression in mind, and allowing them plenty of room to swim, hide, and stake out territory without the need for violence.

Things You'll Need

  • Aquarium
  • Sand substrate
  • Heater
  • Filter
  • Lighting
  • Thermometer
  • Aquarium test kit
  • Rocks and decor
  • Nitrogen cycle starter
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Instructions

    • 1

      Purchase a tank no smaller than 55 gallons depending on the number of Jack Dempsey cichlids you plan to keep. A pair of Dempsey's can be housed in a 75 gallon tank. Though small breeding colonies of several pairs can sometimes be kept in a large enough tank (75 gallons per pair), Jack Dempsey's are highly territorial when breeding, and have been known to aggressively attack other fish even in very large aquariums.

    • 2

      Line the bottom of the aquarium with 2-3 inches of aquarium sand. Jack Dempsey's like to dig, and will create concave nests in the substrate at breeding time. Sandy substrates prevent the fish's mouth and fins from becoming damaged on sharp edges while they dig.

    • 3

      Create plenty of hiding places and visual dividers in the tank using rocks, driftwood, or plastic plants (live plants will quickly be uprooted). These visual barriers are especially important if other fish are to be kept in the tank, as they will allow your fish to establish personal territories and to hide when they feel threatened.

    • 4

      Install the heater, filter, and lighting, always making sure that the equipment you have purchased is appropriate for the size of your tank.

    • 5

      Fill the tank with dechlorinated water, and turn on the equipment.

    • 6

      Purchase a new tank cycle-starting product, available at most specialty fish stores and some pet supply chains, and follow the package instructions carefully over the next few weeks to ensure optimum water quality. Starting the tank's nitrogen cycle with a chemical additive prevents stress on the fish once they are acquired.

    • 7

      Stock the tank with similarly sized non-aggressive fish if you must keep more than just Jack Dempsey's in the tank. Plecostomus are kept with success by many Dempsey owners, but be aware of the potential for your Jack Dempsey to coexist peacefully one day, and abruptly change his mind another.