Do Fish Tanks Really Need Gravel? [Pros and Cons]

While not strictly necessary, gravel is highly recommended for fish tank setup. Gravel in fish tanks serves multiple purposes, such as providing a natural-looking environment for the fish, acting as a biological filter, and aiding in the growth of beneficial bacteria that help in the nitrogen cycle.

It also helps anchor plants and provides hiding places for smaller fish species. Moreover, the texture of the gravel helps to maintain the fish’s natural behavior by allowing them to dig and forage for food.

Overall, gravel is an essential component in fish tanks, contributing to the health and well-being of the fish and the overall aesthetic appeal of the aquarium.

A nice aquarium set up with colorful gravel, and pebbles
A nice aquarium set up with colorful gravel, and pebbles

What Is Aquarium Gravel?

Aquarium gravel placed on the bottom of the tank, is a type of substrate commonly used in fish tanks and aquariums. It consists of small, smooth, and rounded particles made from various materials, such as natural stones, pebbles, or specially designed synthetic materials.

The gravel is spread along the bottom of the aquarium to create a functional and aesthetically pleasing environment for the aquatic inhabitants.

What Is Aquarium Gravel Made Of?

Aquarium gravel is available in a variety of materials, each offering unique benefits. Some common materials used for aquarium gravel include:

  • Natural gravel: This type of gravel is sourced from natural deposits and is available in various sizes, shapes, and colors. It is often preferred for its natural appearance and compatibility with different fish species.
  • Colored gravel: Colored gravel is popular among aquarium enthusiasts due to its vibrant appearance. It is typically made by dyeing natural gravel with safe pigments, providing a range of options to match your tank’s theme.
  • Coated gravel: Coated gravel consists of smooth stones that are covered with resin or polymer coatings. This type of gravel offers a uniform look and prevents the release of harmful substances into the water.
An aquarium with different size, and shape gravel bed
An aquarium with different sizes, and shapes of gravel bed

Do You Need Gravel In A Fish Tank? [Pros And Cons]

Adding gravel to a fish tank is a common practice among aquarium enthusiasts. It not only enhances the aesthetic appeal of the tank but also provides several benefits for the fish and the overall tank ecosystem. However, there are pros and cons to consider before deciding whether or not to include gravel in your fish tank setup.

What Other Fishkeepers Think On The Gravel Requirements?

I did one survey among the fishkeeping community regarding gravel requirements in a fish tank. I questioned, “Is gravel necessary for a fish tank?”, and people willingly voted for different options.

The summary is, 72% opined gravel is beneficial for fish tanks. Among them, some fishkeepers think although gravel is beneficial it’s not a necessity. Only a few (11%) prefer sand over gravel. You can see the result in the below pie chart.

Do fish tanks need gravel (General Consensus)
Do fish tanks need gravel (General Consensus)

The Practical Benefits Of Gravel In A Fish Tank

  • Proper filtration: Gravel plays a crucial role in maintaining the filtration system of your fish tank. It acts as a mechanical and biological filter, trapping debris and waste, and providing a surface for beneficial bacteria to grow and break down toxins.
  • Biological balance: The gravel substrate provides a habitat for beneficial bacteria that help in the nitrogen cycle. These bacteria help convert toxic ammonia, produced from fish waste, into less harmful substances, promoting a healthy environment for your fish.
  • Root anchoring: If you plan to have live plants in your fish tank, gravel serves as a foundation for them. The plants’ roots can anchor themselves in the substrate, promoting their growth and stability.
  • Easy to clean: With regular maintenance, gravel can be easily cleaned using a siphon to remove debris and excess waste from the tank.
A beautifully set up tank with gravel, decors, and plants
A beautifully set up tank with gravel, decors, and plants

Aesthetic Advantages Of Aquarium Gravel:

  • Natural look and feel: Gravel comes in various colors and sizes, allowing you to create a natural-looking environment for your fish. It replicates the riverbed or seabed, enhancing the overall appearance of your aquarium.
  • Hiding spot for shy fish: Some fish species prefer to have hiding places in their tanks. Gravel can offer them hiding spots, making them feel more secure and reducing stress.
  • Enhanced colors of fish: Certain species of fish exhibit brighter and more vibrant colors when they are surrounded by a suitable gravel substrate. This can significantly improve the visual appeal of your aquatic pets.
  • Prevents reflection: The presence of gravel helps reduce the reflection of light in the tank, minimizing stress for the fish.

Aquarium gravel is a multi-functional component of fish tanks. It provides practical benefits like supporting biological filtration, acting as a nutrient-rich substrate, and aiding in waste containment.

Additionally, it enhances the aesthetics of your aquarium by creating a natural look and feel, providing hiding spots for fish, and intensifying their colors.

Related Post:

Gravel bed planted aquarium
Gravel bed planted aquarium

The Cons Of Having Gravel In A Fish Tank

  • Accumulation of debris: Gravel can trap uneaten food and waste, making it harder to clean and maintain proper water conditions. It requires regular vacuuming to prevent the build-up of harmful substances.
  • Choking hazard: Small gravel pieces can be swallowed by fish, especially smaller or bottom-dwelling species. This can lead to choking or intestinal blockages, posing a risk to their health.
  • Limited oxygen flow: Thick layers of gravel can restrict oxygen flow to the beneficial bacteria residing within it. This can affect the efficiency of the biological filtration process.
  • Restricted plant choices: Certain plant species have specific substrate requirements and may not thrive well in gravel. Consider the types of plants you wish to incorporate in your tank before deciding on the substrate.

While adding gravel to your fish tank offers numerous benefits, it is crucial to weigh the pros and cons based on your specific tank setup and fish species.

Understanding the impact of gravel on the filtration, aesthetics, and overall well-being of your aquarium ecosystem will help you make an informed decision.

When Gravel Isn’t Necessary?

While gravel can enhance the aesthetic appeal of a tank and provide a natural habitat for certain species, there are instances where it may not be needed.

Let’s explore when gravel may not be necessary for your fish tank.

Bare Bottom Tanks:

  • Bare bottom tanks, as the name suggests, are aquariums without any substrate or gravel. This type of setup is commonly used in breeding tanks and quarantine tanks.
  • A bare-bottom tank offers several benefits, including easy maintenance, reduced risk of toxins accumulating, and better water flow. Without gravel, waste and leftover food are more easily removed, resulting in a cleaner environment for your fish.

Specially Designed Tanks:

  • Some fish tanks are designed with specific needs in mind, such as planted tanks or reef tanks. These setups often require a different type of substrate, like sand or coral rubble, to create the optimal environment for the plants or corals.
  • In these cases, gravel may not be necessary, and using a different substrate will provide better conditions for the plant or coral growth.
Bare bottom breeding tank
A bare bottom breeding tank

Fish Species:

  • Certain types of fish prefer a bare-bottom tank or require specific substrate conditions. For example, some bottom-dwelling fish, like corydoras catfish, prefer a sandy substrate that mimics their natural habitat.
  • Additionally, fish that have delicate fins, such as bettas, may also benefit from a tank without gravel to prevent fin damage.

Ease Of Cleaning:

  • Gravel can make cleaning your fish tank more challenging, as waste and debris can become trapped in between the rocks. This can lead to ammonia spikes and negatively affect water quality.
  • In situations where ease of cleaning is a priority, such as in busy households or for beginners, maintaining a tank without gravel can simplify the cleaning process and contribute to better water conditions.

While gravel can be a valuable addition to a fish tank, there are instances where it may not be necessary or even beneficial.

Factors such as the type of tank setup, fish species, and ease of cleaning all play a role in determining whether or not gravel is needed. Consider these aspects when deciding if gravel is right for your aquarium setup.

A bare bottom fish tank
A bare bottom fish tank

Is It Ok To Create A No Gravel Aquarium? [Bare-Bottom Tank]

While gravel has been a popular choice for many years, there are many types of substrate that can serve a similar purpose to aquarium gravel. So, you can also consider those options.

However, there is another type of aquarium set up which is bare bottom tanks as I mentioned earlier, where there is no substrate. In this section, I’ll discuss the pros and cons of creating a fish tank without gravel, commonly known as a bare-bottom tank.

Pros Of A Bare-Bottom Tank:

  • Easier to clean: Without gravel, it becomes much easier to clean the tank thoroughly. Fish waste and debris can be easily siphoned out, leaving behind a clean and pristine environment for your finned friends.
  • Increased water flow: Gravel can sometimes hinder water flow in the tank, especially if it’s not properly maintained. A bare-bottom tank provides better water circulation, ensuring a healthier and oxygen-rich environment for your fish.
  • Visual clarity: With no gravel to hide beneath, your fish become the main focal point of the tank. Their vibrant colors and interesting behaviors are more easily observed in a bare-bottom tank, creating a stunning visual display.
  • Prevents accumulation of harmful materials: Gravel can trap uneaten food, fish waste, and excess debris, leading to the release of harmful chemicals into the water. A bare-bottom tank eliminates this concern, reducing the risk of water pollution.

Cons Of A Bare-Bottom Tank:

  • Lack of natural habitat: Gravel provides a natural substrate that mimics the substrate found in natural aquatic environments. Without gravel, the tank may lack the natural look and feel that some fish species prefer. Additionally, certain bottom-dwelling fish may not have suitable surfaces to forage for food.
  • Diminished biological filtration: Gravel can serve as a home for beneficial bacteria, crucial for biological filtration in the tank. Without gravel, it may take longer for the tank to establish a balanced and stable ecosystem.
  • Increased stress for some fish: Certain species of fish may feel exposed and stressed in a bare-bottom tank. Fish that rely on hiding spots or burrowing in the substrate may experience heightened anxiety in a tank without gravel.
  • Less interesting aesthetics: For many aquarists, the aesthetics of a tank are just as important as its functionality. Gravel can provide an attractive and natural-looking substrate, enhancing the overall visual appeal of the tank.

The decision to create a bare-bottom tank depends on your specific circumstances, preferences, and the needs of your fish species.

While a gravel-less tank offers easier maintenance, better water flow, and improved visual clarity, it may not be suitable for all fish or desired for those seeking a more natural-looking aquarium.

Consider your fish’s needs and your own preferences before deciding to go gravel-free or opt for the traditional gravel substrate.

A bare bottom tank set up with Axolotol
A bare bottom tank set up with Axolotol

Do Betta Fish Need Gravel?

Betta fish is popular fish, and some betta owners ask do betta fish need gravel, or if can they set their betta tank without gravel. Gravel is a common and popular addition to fish tanks, but do betta fish really need it?

The short answer is no. Betta fish do need substrate in their tank. However, gravel is not the only substrate that is perfect for betta fish. There are other options including sand, soil, etc.

Betta Tank with gravel, and plants
Betta Tank with gravel, and plants

Why Gravel Is Not Absolute Necessary for Betta Fish:

  • Betta fish originates from the shallow, slow-moving waters of southeast Asia. In their natural habitat, the substrate is usually sand, mud, or plant matter.
  • Betta fish have long, flowing fins that can easily get caught in gravel. While some artificial gravel options are smoother, there is still a risk of fin damage.
  • The absence of gravel reduces the risk of the betta accidentally ingesting small stones or gravel, which can lead to digestive problems or blockages.
  • Betta fish can be kept in a well-planted tank with live plants. Plants can provide a more natural and aesthetically pleasing environment while also helping to maintain water quality.

If you still prefer to have gravel in your betta fish tank, choose a fine, smooth gravel option without sharp edges to minimize the risk of injury. So, while gravel is commonly used in fish tanks, it is not a necessity for betta fish. However, don’t forget to consider the benefits that gravel provides.

A Goldfish tank under light
A Goldfish tank

Do Goldfish Need Gravel?

Similar to Betta fish, Goldfish do not necessarily need gravel in their aquarium, but it can be beneficial for their overall well-being if used appropriately. Let’s take a closer look at whether goldfish need gravel and the benefits it can provide.

Benefits Of Gravel In A Goldfish Tank

These are the specific benefits gravel can provide for goldfish tanks other than those mentioned earlier for generic fish tanks.

  • Aids in digestion: Goldfish are known to be avid foragers, and gravel can mimic their natural habitat by providing them with opportunities to sift through it and search for food. This process can aid in their digestion by promoting natural feeding behaviors.
  • Prevents uprooting of plants: If you have live plants in your goldfish tank, gravel can provide them with stability, preventing them from being uprooted by the goldfish’s movements.

Factors To Consider:

  • Size of the gravel: When choosing gravel for a goldfish tank, you should opt for larger-sized gravel to prevent the goldfish from accidentally swallowing it. This helps minimize the risk of choking or digestive issues.
  • Goldfish species: It’s important to note that some goldfish varieties, such as the bubble eye or telescope eye goldfish, have delicate eye structures. In such cases, using gravel with sharp edges may pose a risk of injury. Opt for smooth gravel or consider alternative substrates if you have these delicate goldfish breeds.

The Choice Is Yours:

Ultimately, whether to use gravel in your goldfish tank is a personal preference. Understanding the benefits it can provide, as well as the potential factors to consider, will help you make an informed decision. If you do decide to use gravel, ensure it is suitable for goldfish and properly maintain it for a healthy environment.

A bare bottom hospital tank
A bare bottom hospital tank

Frequently Asked Questions For Do Fish Tanks Need Gravel

Do Fish Tanks Need Gravel For Filtration?

Gravel in fish tanks has a dual purpose—decorative and functional. Besides adding an aesthetic appeal to the tank, the gravel also plays a vital role in the biological filtration process. Beneficial bacteria grow in the gravel, breaking down harmful waste substances and maintaining water quality for the fish.

Is Gravel Necessary For Fish Tank Setup?

Yes, fish tanks need gravel as it provides a number of benefits to the aquarium ecosystem. The gravel layer acts as a substrate for beneficial bacteria growth, allowing for biological filtration. Additionally, gravel provides a natural environment for fish, helps anchor plants, and prevents excess food from accumulating at the bottom.

Can I Use Sand Instead Of Gravel In A Fish Tank?

Yes, sand can be used in place of gravel in a fish tank. However, there are some considerations. Fine sand particles can clog filters, leading to water quality issues. It is important to choose a sand type that is suitable for aquarium use and perform regular maintenance to prevent debris buildup.


Gravel in fish tanks is not just a decorative element; it also provides numerous benefits for both the fish and the overall tank’s health. The rough texture of gravel allows beneficial bacteria to colonize, which promotes biological filtration and breaks down harmful ammonia.

Additionally, the gravel acts as a substrate for live plants to root, adding oxygen and stability to the tank. It also serves as a natural habitat for beneficial microorganisms that aid in waste decomposition.

From a design perspective, gravel comes in various shapes, sizes, and colors, allowing you to create a visually appealing underwater landscape. Thus, the inclusion of gravel in fish tanks is not just an aesthetic choice; it plays a vital role in maintaining a healthy and thriving aquatic ecosystem.

Sujit Modak

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