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Choosing the Right Planted Aquarium Substrate: Soil, Gravel, or Sand

Choosing the Right Planted Aquarium Substrate: Soil, Gravel, or Sand

Keeping your aquarium bright and vibrant is not just about choosing the right fish or plants, but also getting the best substrate. Substrates contribute significantly to a tank’s ecosystem by supporting plant growth, housing beneficial bacteria, and providing aesthetic appeal.

In this article, I’ll guide you through the selection process of soil, gravel or sand substrates for your planted aquarium – each offering unique benefits to your aquarium.

Key Takeaways

  • The right aquarium substrate supports plant roots, provides essential nutrients, and enhances aesthetic appeal.
  • Gravel offers a stable base for plant roots and ample space for beneficial bacteria to grow.
  • Soil-based substrates like ADA Aqua Soil Amazonia provide essential minerals and promote lush plant growth.
  • Sand is comfortable for bottom-feeding fish but may hinder plant root growth due to its compactness.

How to Choose the Right Substrate for Your Aquarium

Considerations for substrate selection include the type of plants you want to keep, the desired aesthetic look, and the water parameters needed for your specific fish species.

Considerations for substrate selection

When selecting a substrate there are several key considerations to keep in mind. First and foremost, think about the type of plants you want to keep. Some plants, such as root feeders like Amazon swords or crypts, require nutrient-rich substrates like soil or clay-based substrates to thrive.

On the other hand, if you prefer low-maintenance plants like Java ferns or Anubias barteri that rely on water column feeding, gravel or sand may be sufficient.

Another important factor is the needs of your fish and tankmates. Certain species, such as corydoras catfish or loaches with delicate barbels, benefit from a soft substrate that won’t harm their sensitive bodies.

Additionally, consider the aesthetic appeal and desired look of your aquarium. Gravel comes in various sizes and colors and can create a natural appearance while still allowing for easy cleaning.

Types of Plant Substrates

There are three main types of aquarium substrates: gravel, sand, and soil.

Gravel Substrate

Gravel, a popular choice for novice aquarists, offers an affordable and attractive option for aquarium substrates. Its structure promotes good water circulation and aids in nutrient cycling within the tank due to its coarse texture.

This rocky substrate can support live aquatic plants since it provides a stable base for their roots. However, unlike soil-based substrates or certain sands, gravel does not supply minerals essential for plant growth.

Also noteworthy is that some types of gravel could have ragged edges dangerous to bottom-feeding fish like corydoras and loaches. Despite this, many appreciate gravel’s durability and ease of maintenance—yes, it requires cleaning but proves simpler than its counterparts.


  • Gravel is affordable and has a variety of styles available, making it a popular choice for beginners.
  • It allows for live aquatic plants to be planted, offering them a secure place for their roots.


  • Gravel does not provide the necessary minerals for plant growth.
  • If not cleaned properly, it can harbor debris and waste, leading to poor water quality.
  • It may compact over time, affecting root growth.

Soil Substrate

Soil substrates are an excellent choice for a planted aquarium as they provide a natural and aesthetically pleasing look to the tank. They also serve as a solid foundation for plant root development.

One of the key benefits of soil substrates is their nutrient-rich composition, which helps promote healthy plant growth. Additionally, soil substrates support the growth of beneficial bacteria that aid in maintaining water quality by breaking down fish waste and detritus.

With its combination of visual appeal and functionality, soil is a great option to consider when choosing the right substrate for your planted aquarium.


  • Soil promotes vigorous plant growth due to its rich nutrient content.
  • It alters the water chemistry, lowering the pH and making the water softer, which can be beneficial for certain fish and plants.


  • Soil may cloud the water initially, requiring additional filtration or water changes.

Sand Substrate

Sand is a popular choice for aquarium substrate, especially for tanks with bottom-feeding fish or those with soft bellies. It is finer and softer than gravel, providing a comfortable surface for these types of fish.

One advantage of sand is that it can be easily cleaned by hovering a siphon over any debris without disturbing the substrate too much. However, extra caution should be taken to avoid removing too much sand during cleaning as it can potentially damage equipment like filters and pumps if kicked up into the water.

It’s worth noting that while sand can create an aesthetically pleasing look in your tank, it may not be the best choice for live plants due to its compactness which can hinder plant root growth.


  • Sand is ideal for bottom-feeding fish or those with soft underbellies.
  • Cleaning is relatively easy, as debris sits on top of the sand, and can be easily siphoned off.


  • Care must be taken when cleaning, as excessive removal of sand can disrupt the ecosystem.
  • If stirred up into the water, sand can potentially damage aquarium equipment such as filters and pumps.

Best Substrates For Planted Tanks

Now let’s dive into a review of the best substrates for your planted aquarium. From ADA Aquasoil Amazonia to Seachem Flourite, we’ll explore their features and benefits.

ADA Aqua Soil Amazonia

ADA Aqua Soil Amazonia is a favored substrate among planted aquarium enthusiasts. It is known for its nutrient-rich composition that supports healthy plant growth. This substrate has the ability to alter water chemistry by lowering the pH and making the water softer.

However, it’s important to note that ADA Aquasoil Amazonia may release ammonia initially, which can harm fish and encourage algae growth. Despite this, it remains an excellent choice for root-feeding plants in your aquarium.

Mr Aqua Aquarium Soil Substrate

Mr Aqua Aquarium Soil Substrate is a specially formulated substrate designed specifically for planted aquariums. It provides essential nutrients for plant growth, making it an ideal choice for aquarists looking to create a thriving underwater landscape.

Compared to ADA Aqua Soil, Mr Aqua Aquarium Soil Substrate contains less ammonia, ensuring a healthier environment for your aquatic plants and fish. While similar to ADA Aqua Soil in composition, Mr Aqua Aquarium Soil Substrate has a lower nutrient content.

Additionally, this substrate may be less crumbly and visually appealing compared to ADA Aqua Soil, adding an extra touch of aesthetic charm to your tank.

Seachem Flourite

Seachem Flourite is a popular choice among aquarium enthusiasts for planted tanks. This substrate is inert, meaning it does not provide nutrients to plants directly. However, its small and porous grains promote water circulation and oxygenation in the tank.

Seachem Flourite is especially beneficial for root-feeding plants as it creates a stable environment for healthy root development. One of the key advantages of using Seachem Flourite is that it does not release any harmful substances into the water, making it safe for both fish and invertebrates in your aquarium.

CaribSea Eco-Complete

CaribSea Eco-Complete is a highly regarded substrate choice for planted aquariums. It is packed with nutrients that promote healthy root growth, making it ideal for supporting aquatic plant life.

This volcanic soil substrate also creates a biological balance in the tank, enhancing water quality and aiding in the establishment of beneficial bacteria. With its nutrient-rich composition and ability to support plant growth, CaribSea Eco-Complete is considered one of the top substrates available for planted aquarium enthusiasts.

Understanding the Role of Substrate

The substrate in a planted aquarium plays a crucial role in supporting plant roots, providing essential nutrients, and enhancing the overall aesthetic appeal of the tank.

Support for plant roots

Just like terrestrial plants, aquatic plants require a stable base to anchor themselves and thrive. Gravel, with its larger particle size, allows plant roots to spread easily while also offering ample space for beneficial bacteria to grow.

This helps in breaking down fish waste into nutrients. On the other hand, nutrient-rich substrates such as ADA Aqua Soil Amazonia and CaribSea Eco-Complete provide an ideal environment for root feeders by providing essential minerals necessary for growth.

These premium substrates not only help strengthen root systems but also foster overall plant health resulting in vibrant aquascapes.

Nutrient provision

Soil-based substrates, like ADA Aqua Soil Amazonia, are packed with nutrients necessary to promote lush plant growth.

These high-quality soils not only feed the plants but also work to lower pH and soften water, creating ideal conditions for many aquatic species.

On the other hand, gravel and sand substrates may lack inherent nutrients. However, they can still support healthy plant life when supplemented with appropriate fertilizers. The secret lies in their high CEC (Cation Exchange Capacity) which enables these substrate types to hold onto nutrients from water and slowly release them over time.

This steady nutrient supply offers an advantage especially helpful for root-feeding plant varieties common in aquarium setups.

Substrates like CaribSea Eco-Complete offer another interesting solution by combining volcanic soil’s nutritional benefits with the aesthetic appeal of dark granules which provide a lovely contrast against colorful fish and vibrant plants while also promoting root growth and balancing biological aspects within the tank.

Create aesthetic appeal

Substrate greatly contributes to the aesthetic appeal of a planted aquarium. Choosing between soil, gravel or sand can fundamentally change the visual impact of your tank. Soil offers an authentic and natural look, while gravel provides eye-catching color options and dramatic texture variations.

On the other hand, sand ensures a smooth and sleek appearance which is particularly appreciated in minimalist aquascapes. The choice of substrate should complement your aquatic plants, drawing attention without dominating the view.

By coordinating colors, grain sizes, and textures with your chosen plant species and hardscape elements, you can create stunning underwater sceneries that captivate viewers at first glance.

However, it’s important to remember that aesthetics shouldn’t override functionality for thriving plant growth; striking a balance between visual interest and biological needs is crucial in successful aquascaping.

Substrate selection does not only define how well your plants will grow but also how breathtaking they’ll appear underwater when properly illuminated.

How to Apply Substrate in Your Aquarium

To apply substrate in your aquarium, follow these steps:

  1. Prepare the tank by rinsing the substrate under running water to remove any dust or debris.
  2. Create a slope at the back of the tank by adding more substrate to one side and gradually decreasing it towards the front.
  3. Gently pour the substrate into the tank, being careful not to disturb any plants or decorations already in place.
  4. Use your hands or a flat tool to spread the substrate evenly across the bottom of the tank.
  5. Smooth out any uneven areas and ensure that there are no large pockets of air between the substrate particles.
  6. If you plan on using multiple layers of different substrates, add them one at a time, starting with the coarsest material at the bottom.
  7. Once all the substrate is added, carefully fill your tank with water, pouring it slowly to avoid disturbing the arrangement of the substrate.
  8. After filling, use a net or your hand to gently remove any floating particles or loose debris from the surface of the substrate.
  9. Allow your aquarium to cycle for several days before adding fish or plants.


Why consider different substrates when starting a new aquascape project?

Different substrates offer varying nutrient exchange capacities (cec), affect pH levels, water hardness and can either enhance or limit plant growth depending on their composition.

Can using regular aquarium gravel have an impact on my planted tank?

Regular aquarium gravel provides filtration and supports root systems but lacks essential nutrients that specialty substrates like soil or clay-based products (flourite, eco-complete) provide aiding efficient plant growth.

Does the size of substrate granules matter in a planted tank?

It sure does. Coarse sand or finer granules are recommended especially when keeping bottom-dwelling tropical fish like corydoras or loach; larger pebbles may cause injuries to these species.

Can I mix different types of substrate in my Planted Aquarium?

Absolutely. Many aquarists often layer nutrition-rich soils under decorative gravels which not only gives a natural look but also maximizes benefits supporting optimal live plant growth.

Wrapping Up

Choosing the right substrate for your planted aquarium is crucial for the health and growth of your plants. Here are some key points to remember:

  • Substrate provides a base layer for plant roots and offers a home for beneficial bacteria.
  • Different substrates can impact water parameters like pH and hardness. which may benefit certain fish species.
  • Gravel is an affordable option with various styles available.
  • Sand works well for bottom-feeding fish or those with soft bellies.
  • Consider using a combination of substrates to meet both functional and aesthetic goals.

By selecting the appropriate substrate, you can create a thriving ecosystem in your tank that enhances the beauty of your aquatic plants while providing optimal conditions for their growth.

I’m Elle, the founder of FishHQ. I created this website to share knowledge, tips, and inspiration for beginner hobbyists to help them create a healthy, happy, and vibrant environment for their fish to thrive. Read more...