How to Replace a Substrate in a Salt Water Tank

Marine fish and invertebrate animals such as starfish, corals and anemones produce metabolic waste, which fouls the aquarium. Much of this organic waste eventually gathers on the tank substrate, which requires periodic replacing. It is possible, by working carefully, to replace the aquarium substrate without draining all the water and removing the fish. Periodically replacing the aquarium substrate should be considered as an important maintenance tasks if you are keeping a salt water tank.

Things You'll Need

  • 15-gallon aquarium
  • Two 10-gallon buckets
  • 3-foot long piece of transparent plastic pipe
  • Three old towels
  • Two long handled, fine weave aquarium nets
  • Garden tap
  • Sturdy plastic stick
  • Long handled plastic aquarium tong
  • 5-lbs. replacement substrate
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Instructions

    • 1

      Turn off the wall plug and switch off aquarium heaters and pumps.

    • 2

      Place a number of old towels on the floor in front of the aquarium.

    • 3

      Drain 5-gallons of aquarium water into a 10-gallon bucket, using a piece of 3-foot long transparent plastic tubing. Place one end of the pipe into the aquarium and hold it in place, just off the gravel. Place the opposite end in your mouth and suck powerfully until you see the water moving up the pipe. Remove the pipe from your mouth as soon as water begins to flow into it and place the end into the bucket.

    • 4

      Remove the various pieces of rock from one half of the aquarium and place them into the10-gallon bucket, containing the aquarium water. Remove any pieces of live coral or any other creature that is on the substrate, on the side that you will replace. Place these in the 10-gallon bucket.

    • 5

      Place and hold the first long handled net into the aquarium, resting on the substrate. Use the second net to gently push substrate into the first net. Remove the net once it is full and place the dirty substrate into the second 10-gallon bucket.

    • 6

      Continue in this way until all the substrate on the one half of the tank has been removed. Only replace one half of the substrate at a time, or you will destroy all the beneficial bacteria living on the bottom of the aquarium.

    • 7

      Deposit the replacement substrate in a bucket and half fill the bucket with water.

    • 8

      Stir this new substrate with a sturdy plastic stick to remove dust and residual dirt from the packaging.

    • 9

      Tip the dirty water out and repeat, until the new substrate is dust free.

    • 10

      Fill a long handled net with replacement substrate and place the net carefully into the aquarium. Hold the net just above the bare glass floor, and, using the long plastic aquarium tongs, take hold of the bottom of the net and gently tip the substrate out.

    • 11

      Repeat until all the replacement substrate has been added to the aquarium.

    • 12

      Return all the rocks and corals to the aquarium.

    • 13

      Gently pour the aquarium water from the bucket back into the aquarium.

    • 14

      Wait a week and replace the other half of the substrate.