Gravel is a critical element of any fish tank, providing essential nutrients and improving the aesthetic appeal of your aquarium. However, it can be difficult to know which type of gravel is best for your tank.
In this article, we will explore the importance of gravel in a fish tank, discuss the different types available, and answer common questions about how deep gravel should be.
Why Is Gravel Important In A Fish Tank?
If you’re wondering whether you should consider adding gravel to your fish tank, the answer is yes. Gravel helps make a fish tank look better and provides important benefits for the fish and the tank. Here are 7 reasons why gravel is essential in a fish tank:
Gravel Helps Create A Natural Environment
It provides a surface for beneficial bacteria to colonize, which helps maintain a healthy tank environment and keep the water clean. The gravel also provides an area for fish to explore and hide, which can help reduce their stress levels and make them feel more comfortable.
Gravel Helps Keep The Aquarium Clean
The tiny spaces between the rocks allow debris and waste to settle so that it can be easily removed by filtration or during a water change. Gravel also helps keep the water from becoming too murky or cloudy because it traps small particles that would otherwise cloud up the tank.
Gravel Keeps Aquarium Ph Levels Stable
Gravel buffers the pH of aquarium water, preventing sudden increases in acidity and alkalinity that can harm fish. The presence of gravel also stabilizes ammonia levels in the water.
Gravel Provides Home For Beneficial Bacteria
Beneficial bacteria live in the spaces between rocks and help break down ammonia into nitrate, which is essential for healthy tanks. These bacteria are a crucial part of any biological filtration system, so having some gravel is essential for your tank to stay healthy.
Gravel Helps Reduce Shock In Fish
Fish can become stressed or even suffer from shock when moved from one tank to another. The presence of gravel helps make the transition less stressful by providing a familiar surface for them to explore and hide in.
Gravel Adds Aesthetic Value
Gravel is available in many different colors and sizes, so you can choose the kind that best suits your tank’s decor. It also adds visual interest to the substrate’s otherwise bland bottom layer.
Gravel Is Relatively Cheap, And Easy To Maintain
Gravel is inexpensive compared to other substrates and doesn’t need much maintenance beyond occasional vacuuming. This makes it a great option for those who don’t want to spend too much time or money on aquariums.
Supports Plant Growth
Gravel helps support the growth of live plants in your aquarium, as it provides an anchor for their roots to take hold and spread out. Live plants help oxygenate the water, provide shade, and create shelter for the fish.
What To Look For In Gravel When Selecting Gravel For Your Fish Tank?
In choosing gravel for fish tanks, there are a few things that you should consider. Here are five key areas to look at when selecting the best gravel for fish tanks:
1. Color
The best gravel for fish tanks should be a neutral color. This will allow the colors of your fish and plants to stand out more. Avoid any gravel that has a strong hue, as this can overpower the colors of your fish and plants.
2. Size
Your fish tank gravel should be small enough so that your plants have plenty of space to grow but also large enough that they don’t get sucked up into the filter. You should also consider how deep the gravel needs to be in order to best house the fish.
3. Texture
Fihs tank gravel should be smooth and not too sharp, with no jagged edges or rough spots. This will make it comfortable for your fish to swim around in and help protect them from any abrasions.
4. Natural or Synthetic
You should also consider whether you want natural or synthetic gravel for your fish tank. Natural gravel is typically made of various minerals, rocks, and pebbles which are collected from rivers and streams. Artificial aquarium gravel usually consists of resin beads, crushed glass or plastic pellets.
5. Price
Generally speaking, natural gravel is more expensive than synthetic aquarium gravel due to its rarity and complexity in sourcing. However, many feel it is worth the price for its aesthetic beauty and potential health benefits for fish tanks.
What Are The Different Types Of Aquarium Gravel
Aquarium gravel comes in various sizes and colors, so finding the right look for your tank is easy. Here are some of the most popular types of aquarium gravel:
Natural Gravel
Natural gravel is just what it sounds like—gravel straight from nature that has been collected or mined. It is available in many different colors and sizes, making it an ideal choice if you want to create a natural-looking environment in your tank.
Colored Gravel
Colored gravel is made by coating natural stones with a pigment. This type of gravel adds bright pops of color to your tank and can be used to match any decorating style.
Aragonite Gravel
Aragonite gravel is made from crushed coral skeletons, containing calcium and other beneficial minerals. It is available in various colors, including white, tan, and even red.
Plant Substrates
Plant substrates are designed to provide an ideal environment for live plants. They usually contain fertilizer or special clay pellets that release nutrients into the water over time.
Aquarium Sand
Aquarium sand is a popular choice for tanks with bottom-dwelling fish because it won’t cloud up like gravel can when disturbed. It also looks very natural and can be used to create a beach-like atmosphere in your tank.
Crushed Coral
Crushed coral is made from the skeletal remains of corals and marine organisms. It buffers pH levels in the tank, making it an excellent choice for saltwater aquariums.
Fluorescent Gravel
Fluorescent gravel contains phosphors that can glow brightly under certain light conditions, adding a fun and unique effect to your aquarium décor. These pebbles are usually relatively small, so they can be used as a substrate or for decoration.

Best Gravel For Fish Tanks
The best gravel for fish tanks should be safe and provide a healthy environment for your fish. We listed the best aquarium gravel as varied as possible. On the list of products, there are different brands and combinations of gravels with different benefits.
1. Carib Sea Eco-Complete – Best Overall
CaribSea Eco-Complete Aquarium Substrate is an entirely natural substrate that is packed full of beneficial bacteria, minerals, and trace elements. This gravel will provide an ideal environment for plants to thrive and helps maintain natural water chemistry.
Pros:
- Helps to maintain natural water chemistry
- Contains beneficial bacteria and trace elements
- Perfect substrate for plants to thrive in
Cons:
- Can be slightly more expensive than other aquarium gravel
2. GloFish Aquarium Gravel
GloFish Aquarium Gravel comes in different amounts and color combinations. The gravel gives your fish and plants a beautiful, safe, and colorful place to stand. The few pieces of gravel with fluorescent accents will change the look and feel of the aquarium.
Pros:
- Available in multiple color options
- Smooth, and fish can swim on it
- Has a mix of fluorescent colors
Cons:
- While cleaning, paint is easy to chip
3. Seachem Flourite Black Clay Gravel
Seachem Flourite Black Clay Gravel is a good choice if you have a bioactive freshwater tank. This natural clay substrate is porous and perfect for plants. Depending on your needs and preferences, you can also mix this type of gravel with other types of gravel. It’s easy to use and set up the Seachem for your live plants.
Pros:
- Natural
- Won’t change the pH level
- Doesn’t have to be changed
- Good for tanks with live decorations
- Can be used with filters that go under the gravel
Cons:
- Only for tanks with live plants and freshwater
- It takes days to settle
- Rough texture
5. Spectrastone Special Blue Aquarium Gravel
Spectrastone Special Blue Aquarium Gravel is great unique gravel which works well in freshwater aquariums and helps fish and plants live together. The aquarium gravel’s dark and bright blue color is a win, especially in terms of how it looks. The outside of the gravel is made with a non-toxic coating.
Pros
- Smooth and polished texture
- Bright colors make tanks look better
- Non-toxic coating
Cons
- Not easy to clean
6. AquaNatural Gold Pearl Gravel
AquaNatural Gold Pearl Gravel Substrate is another type of gravel for plants that is often used in aquariums. Unlike the bigger pieces, these come with small pieces of gravel that can be used as a bed in the aquarium. All of the gravel in the bags is found in nature, so you no longer have to worry about toxic paint or chemicals.
Pros
- Tiny, light-weight pieces
- Uniform shape and size
- It is 100% natural and doesn’t change pH
Cons
- Could make the aquarium appear drab
7. Exotic Pebbles Polished Mixed Gravel
Lastly, Exotic Pebbles Polished Mixed Gravel is another top choice for aquarists. It comes in different sizes, and each one is shaped differently. You won’t find any small pieces that will get stuck in your filter or hurt your fish or animals. It’s suitable for the environment, and the brand doesn’t use much packaging.
Pros:
- Different sizes, shapes and colors
- Good for the environment
- Simple to clean
Cons:
- New bags can have a faint chemical smell
How Deep Does Aquarium Gravel Need To Be?
Aquarium gravel should be deep enough for fish to hide in but shallow enough for them to access the bottom and surface easily. Generally, having at least 3 inches of gravel in your aquarium is best. If you’re using it as a substrate for live plants, then 4-6 inches is ideal.
Additionally, if you are setting up a saltwater tank with corals, you will need more than 6 inches of the substrate, so the coral has enough room to spread its roots and securely attach itself.
In this instance, 8-12 inches of the substrate should suffice. It is also essential to ensure that the gravel is evenly distributed throughout the tank to provide good hiding places for fish and reduce water flow.
FAQ
What Color Gravel Is Best For Fish Tank?
The type and color of gravel you choose for your tank should depend on the fish and plants living there. Natural colors such as brown, tan, or white are generally a safe bet as they will create a natural-looking environment in the tank. However, brighter colors can also add pops of color to your aquarium décor.
How Much Gravel Do I Need For My Aquarium?
The amount of gravel you’ll need for your tank will depend on the size and shape and the type of substrate you’re using. Generally, you should aim for at least 3 inches of gravel if it’s just being used as a decorative feature and 4-6 inches if you’re using it as a substrate for live plants.
Gravel Vs. Sand
The choice between gravel and sand will depend on your aquarium type. Gravel is generally more suitable for freshwater tanks because it won’t cloud up when disturbed. Sand can be used in saltwater tanks, however, as it creates an ideal environment for bottom-dwelling fish and corals.
What Are The Benefits Of Using Aquarium Gravel?
Aquarium gravel has many benefits, including improving the aesthetics of your tank, providing a good hiding place for fish, and buffering pH levels. In addition, gravel can also help grow beneficial bacteria in your tank, essential for maintaining a healthy environment for your fish.

Recap
Adding gravel to your tank is a great way to create a safe and healthy environment for your fish. Not only does it look good, but it also provides significant benefits that help keep the tank clean and healthy for the long term. With all these advantages, there’s no reason not to include gravel in your aquarium setup!