How to Prepare Gravel and Substrate for a New Aquarium

By
Shirlie Sharpe
Shirlie Sharpe
Shirlie Sharpe is an aquatic expert and writer with over three decades of experience keeping and raising ornamental fish. She has consulted with The Minnesota Zoo and the National Aquarium. Shirlie has also authored a book on setting up aquariums.
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Updated on 01/16/26
Reviewed by
Nick Saint-Erne
Nick Saint-Erne, DVM
Reviewed by Nick Saint-Erne
Dr. Nick Saint-Erne, DVM, is a highly accomplished veterinarian and writer who has treated zoo animals and exotic pets for more than 35 years. He has worked with the Centers for Disease Control and Prevention to improve pet store animal care among other endeavors. Dr. Saint-Erne is part of The Spruce Pets' veterinary review board.
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Wall mounted aquarium with tropical fish
Credit: Leonid Eremeychuk / Getty Images

Key Takeaways

  • Always rinse new aquarium gravel thoroughly to remove harmful dust, debris, and residues before adding it to the tank.
  • Use a bucket and sieve to clean gravel, ensuring water runs clear to avoid cloudy aquarium water.
  • Avoid pouring gravel rinse water into drains; instead, dispose of it outdoors to prevent plumbing issues.

Did you know that new gravel must be rinsed before putting it into the aquarium? Don't worry, it only takes a few simple steps. Here's what you need to know.

  • Difficulty: Easy
  • Time required: 20-30 minutes

What You Need

  • 6" or larger sieve
  • 5-gallon bucket

Instructions

  1. Purchase enough gravel to cover the aquarium bottom approximately 2-3 inches deep.
  2. If you don't already have one, purchase a 5-gallon bucket and label it for aquarium use only. Aquarium buckets should never have soap in them.
  3. Place a large clean sieve, at least 6 inches across, over the bucket. Fill the sieve half full of gravel.
  4. Pour water over the gravel in the sieve, while gently shaking it. Rinsing the gravel over the bucket rather than over a drain allows gravel that slips through the sieve to be caught instead of going down the drain. Continue pouring water over the gravel until the water runs clear. Several washings are usually required.
  5. Once the water runs clear, the gravel is ready to be used. It may be placed directly into the tank or in a clean bucket or container.
  6. Repeat steps three through five until you have washed enough gravel to fill the aquarium 2-3 inches deep.

Tips

  • A rule of thumb for the amount of gravel to use is one to two pounds of gravel per each gallon capacity in the tank.
  • Old buckets may be used if they are thoroughly cleaned with bleach, rinsed well, and allowed to air dry.

An Alternative Cleaning Method

To properly clean new aquarium gravel, it must be done correctly!

Cleaning new aquarium gravel properly is an important first step in keeping water quality high; gravel dust and residue can harm or even kill fish. Although manufacturers may market new aquarium gravel as 'pre-rinsed' or 'pre-cleaned,' these bags often contain dust, debris, grit, or harmful residues from the packaging process. These small particles should not make their way into a freshwater aquarium environment.

Fish Keepers often think these small particles causing temporarily cloudy water can be removed by an aquarium filter. This is partially true, however, much of the "dust" settles to the bottom of the tank, only to be stirred up whenever the gravel is disturbed. Improperly cleaned gravel is one of the major hidden causes of slightly cloudy water in newer aquariums.

The dye used in cheap gravel available at a low cost can discolor tank water as well as introduce poisons to your fish community. Having colored tank gravel could be your choice, but unless it is completely cleaned, it can be a long term danger to many fish.

The simplest way to start cleaning aquarium gravel is by pouring one bag at a time into a bucket outside your home or office. Conduct this task outdoors to avoid clogging sink drains with gravel dust, which can accumulate and eventually require professional plumbing services. Gravel dust is harmless to lawns or plants, so feel free to pour the water out on the ground, but never into drains.

With a high-pressure hose (normal outdoor water pressure, but with a spray head to increase the pressure at which the water shoots out of the hose) spray an intense stream of water into the gravel at the bottom of the bucket. The water will become cloudy with residue literally washed out of the gravel. Pour out the water covering the gravel in the bucket, again do not pour the water into a drain but on the ground. Repeat over and over until the water above the gravel in the bucket is clear after spraying the gravel. At this point, the gravel is clean enough to put directly into the tank. Empty the next bag of new gravel into the bucket and repeat.

Even after this process, you may have some clouding of the water, this is normal and the dust will settle. Using new gravel is another reason not to put fish in a new aquarium until it has been filled with water and filter allowed to circulate the water for at least a week.

To avoid any clouding of the water, a second step may be necessary. After fully cleaning out the dust and debris using the bucket method, get a large strainer and wash small amounts with the hose to get the last of the dust out of it, and then pour into the new aquarium.

FAQ
  • Is it necessary to rinse pre-rinsed gravel?

    Yes, even if aquarium gravel is marketed as “pre-rinsed” or “pre-cleaned,” it often contains dust and residue that could harm your fish if not properly rinsed.

  • Can I clean aquarium gravel in my kitchen sink?

    It's not recommended to clean aquarium gravel in your kitchen sink as gravel dust can permanently clog the trap, requiring a plumber to fix. Always clean gravel in a bucket outside to avoid this issue.

  • How deep should the gravel be in my aquarium?

    The recommended depth for aquarium gravel is usually about 2-3 inches, or one to two pounds of gravel per each gallon capacity of the tank.

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