Many people assume that the only reason for placing gravel in a fish tank is to make the tank look nicer. If that's so, is it necessary to put in gravel? It's not really necessary, but it is recommended and here's why.

  • Biological Filtration Gravel provides a home for beneficial bacteria that eliminate waste products in the aquarium. If there's no gravel, it's necessary to change the water very often. These useful colonies of bacteria can only thrive in gravel
  • Habitat for the Fish Gravel creates a pleasant habitat for the fish. In a comfortable environment the fish will experience less stress and be much healthier.
  • Aesthetic Appeal Last but not least, gravel makes the aquarium look so much nicer than with a bare tank floor [source: Buzzle].

Now let's see how to clean the gravel in your fish tank.

  1. Fill a bucket half way with dirty fish tank water. Fill the balance of the bucket with clean tap water. You must mix old and new water together so as not to injure the fish by changing the water conditions too drastically.
  2. Place the fish in the bucket.
  3. Unplug all electrical aquarium equipment.
  4. Drain the tank completely.
  5. Take two cupfuls of dirty gravel and put it aside. Since cleaning gravel with chlorinated tap water will destroy most of your friendly waste-eating bacteria, it is imperative to save some gravel with bacteria in it to re-colonize the tank later on.
  6. Take out the rest of the gravel and put it into two buckets.
  7. Place a garden hose into one bucket and turn the faucet on full blast. Vigorously stir and rinse the gravel until you see the water running clear in the bucket.
  8. Repeat the entire process with the second bucket.
  9. Clean the tank with warm tap water. Do not use soap. Clean the filter, thermostat and tubes. Wipe the inside with paper towel.
  10. Put all the gravel back into the tank, mixing together the dirty and clean gravel.
  11. Refill the tank with clean cold tap water. Be sure to add a de-chlorinating agent to the water.
  12. Plug in all the electrical equipment.
  13. Return the fish to the tank [source: Renton].