How to Clean Fish Tank Gravel

By: Contributors  | 

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].


Fish Tank Gravel FAQ

What color gravel looks best for fish tanks?
The color and type of substrate in a fish tank should be as close to the natural environment of the fish and plants as possible. Still, most fish are adaptable, and therefore any color of gravel is fine as long as the tank is well-maintained.
Is gravel good for fish tanks?
Gravel is good for fish tanks, especially freshwater aquariums. It offers biological filtration by providing a home for beneficial bacteria that remove waste products from the tank. It also creates a pleasant habitat for the fish and enhances the aesthetic of aquariums.
How deep should the gravel be in an aquarium?
Depth of gravel is an important factor in a tank. The gravel should be between one and two inches deep (but no more), allowing you to anchor plants, cover an under gravel filter and keep bottom-feeding fish healthy.
Should you clean fish tank gravel?
A dirty substrate is one of the biggest causes of poor water quality in aquariums. While regular water changes remove most of the waste from fish tanks, dirty gravel can contaminate freshwater pretty quickly. Clean the gravel regularly using a siphon or aquarium vacuum.
How often should I clean aquarium gravel?
Aquarium gravel should be cleaned at least once a month using an aquarium vacuum. A few times a year, it can be beneficial to drain all of the water from the tank and remove the gravel, thoroughly cleaning and rinsing it with clean water.