5 Best Substrate for Planted Fish Tanks

If you want a planted tank, the substrate you choose will affect the health of your aquarium. Most plants rely on their root systems for nutrients. In the wild, the plants root themselves on soil, which is why you will need to provide a substrate for your aquatic plants.

In addition to improving the aesthetics of aquariums, substrates also trap waste and prevent it from floating freely in the setup. Some fish species also love to dig in the substrate while looking for food. We reviewed some of the best substrates in the market, including:

Best Substrate for Planted Fish Tanks

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Best Substrate for Planted Fish Tanks

1. Seachem Flourite Black Clay Gravel

This specially fracted porous clay gravel is formulated for a planted tank. The product is manufactured by Seachem, which prides on being an independent pet-care company owned and managed by hobbyists.

Its black color will contrast well to brightly colored fish species as well as the green hues of different plants.

You do not have to use gravel modifiers with this substrate since it works effectively when used alone. It can, however, be mixed with other kinds of gravel substrates.

The substrate is also safe to use, and it will not impact the water’s PH. It provides numerous benefits to a planted aquarium without the need for replacing it.

It will also function well if you have fitted an under gravel filter, and you do not have to be concerned with the substrate decomposing or softening to an unsuitable form within your aquarium.

Once you have your substrate laid up in your tank, pour in the water gently. Note that initial clouding is to be expected, but you can remove it by simply using mechanical filtration.


2. Fluval Plant and Shrimp Stratum

This mineral-rich volcanic soil substrate promises to stimulate the development of your aquatic plants. It has been collected from the foothills of Mount Aso Volcano in Japan that are popular for the minerals they possess.

It is easy for the roots of plants to penetrate and spread throughout this substrate. Your aquatic plants will, therefore,  obtain all the necessary minerals they require to thrive.

The substrate features a light, porous, and non-compacting structure that provides a large surface area for nitrifying bacteria to reproduce. You can expect pristine water conditions by using the substrate.

It supports a neutral to slightly acidic PH that is suitable for most plants and tropical fish. If you rear shrimp in your aquarium, the young ones will seek refuge in the substrate to avoid predation.

The substrate will not discolor your tank’s water, and it will also control the organic discoloration that is common with the use of natural driftwood.


3. Oliver Knott AQUAEARTH Power Plant Growth

This substrate is the result of a partnership between Pisces USA and Oliver Knott. The latter is world-famous for promoting aquascaping and aquadesign. This partnership has bore several aquatic-friendly substrates.

The substrate boasts of a secret formulation of Japanese volcanic ash, clays, and minerals. This unique blend will promote healthy aquatic growth.

Using this substrate is quite easy, and you should first spread it over the aquarium floor. You can utilize a ruler or scraper to level the surface, or you can opt to create gradients within the substrate.

To make planting easier, the water level should be around 3-4cm above the AquaEarth. Spray the plants with water in the course of the planting process. Gradually fill the aquarium to the appropriate level and power up the filtration system.


4. Dennerle Scaper’s Soil Active Substrate

This nutrient substrate is designed to support healthy plant growth. It comes in a deep black hue that will especially contrast beautifully with the green color of aquatic plants.

The substrate is packed with carefully selected natural soils that deliver all the vital minerals and trace elements needed by plants.

The substrate creates slightly acidic, soft water that is ideal for most tropical fish and plants. It features irregularly-shaped grains that promote a natural aesthetic.

The loose characteristic also allows optimum flow through the soil to enable plants to root well.

The substrate also discourages algal growth by having nutrients that mainly benefit the plants instead of the algae. It features a nutrient buffer function, which ensures that nutrients are only directed to the plants when needed.

As long as the aquarium’s plants are healthy, you can be sure that your tank will mostly be free of algae.

You can safely use the soil in combination with CO2 fertilization because it stabilizes the PH.

Its porous surface supports the colonization of cleansing bacteria and makes the substrate a bio-filter. Not only will your tank have excellent water quality but clear water as well.

The substrate also functions as a source of humic and fulvic acids, and it will not discolor your aquarium’s water. It promotes the water conditions that most tropical fish and plants are adapted to in their wild habitats.


5. Carib Sea Gravel for Aquarium (ACS00832)

This substrate has been sourced from the Sri Lankan gravel streams that are popular for their rubies and sapphires. The tiny stones come in a variety of colors to create a stunning effect.

It aims to mimic the natural river eco-systems in your aquarium. The gravel provides a smooth bottom, particularly for bottom-dwelling fish species.

You can use the substrate in soft- or hard-water aquariums since it does not alter the water’s PH. Your plants will easily anchor themselves in this substrate, while the tiny grains will make it easy to vacuum the substrate.


How to Plant Your Aquarium?

How to Plant Your Aquarium?

How to Plant Your Aquarium?

If you desire a planted aquarium, you will have to decide on the substrate and the plants to use. Plants like the Amazon Sword, Anubias, Crypts and Java Fern make excellent starter species. The planting process is made easier by following these steps:

– Add the Substrate

After selecting the substrate to use, you will need to layer it at the bottom of the tank. The depth should be around 3 to 4 inches to accommodate the plants’ growth.

It is also recommended to have more depth at the back sloping to the front. Ensure the grains of the substrate are not too small or large to encourage the plants to root well.

– Add a Small Amount of Water to Cover the Substrate

Add some water to the tank, preferably up to 4 inches high. The water will keep the plants sturdy during planting. Avoid disturbing the substrate by pouring in the water slowly. Some aquarists will break the water’s flow by using a Tupperware lid or a similar object.

– Start Planting Using Tools

You will need aquarium tools to anchor the plants in the substrate.

This toolset by Jeeco has all the equipment you require to plant your plants successfully. You get a curved tweezer, straight tweezer, spatula, and an aquatic curved scissor. All these aquascaping tools are neatly packaged in a velvet couch that you can use to store them when not in use.

Do not be concerned with rust as the tools are made with durable stainless-steel material. The serrated tips on the tweezers will ensure you hold the plants securely for hassle-free planting.

The clip ends are designed with thin and delicate aquatic plants in mind. The tools will barely disturb your water when compared to the disturbance that would be expected when using your hands.

Since these tools are precise, you will not disturb other inhabitants of your aquarium. The spatula is ideal for creating substrate slopes and terraces, while the curved tweezers make it easy to plant.

The planting process is straightforward, and you should start by creating gaps in the substrate. The tweezers will come in handy in placing the roots in the hole.

– Fill the Aquarium After Planting

The final step is adding water to the desired level and activating the heating and filtration systems.

Should You Use Substrate in Your Fish Tank?

Should You Use Substrate in Your Fish Tank?

Should You Use Substrate in Your Fish Tank?

There are different opinions in the aquatic scene on the importance of the substrate. Generally, a tank with a substrate is regarded as more stable when compared to one without.

A bare-bottomed tank has its own advantages and disadvantages, and your fish can survive in it with diligent care. The benefits of having a substrate include:

– Growing Plants

High-quality substrates are formulated with a variety of nutrients that boost plant growth. Some plants are root feeders, meaning that they depend on their roots for nutrients.

The root systems will, therefore, need anchorage in a substrate layer.

Aquatic plants are often divided into those that require a shallow substrate or a deep one. Species like the crypts need a minimum depth of two inches and a half, whereas shallow growers like the hygrophila are fine with a depth of two inches.

Substrates also support plant growth by accommodating the root systems. You have to be careful with the particle sizes, however, as it will determine how well the plants will take root.

If the grains are too small for species like Anubias, they can be uprooted by some fish species.

– Biological Filtration

The substrate serves as a biological medium containing beneficial bacteria. The bacteria play a key role in the nitrogen cycle and eliminate waste in the aquarium.

While the bacteria can reproduce without a substrate, they will not reach adequate quantities to maintain a healthy setting for your fish.

If you opt for a substrate-free aquarium, you will need to do a lot of water changes to avoid the buildup of toxic elements like ammonia.

Regular water changes may, however, not keep up with a large aquarium with a lot of fish, which is why a substrate is necessary.

– Improves the Aesthetics of Your Tank

Substrates come in various colors, sizes, and shapes. When combined with other decorations in the tank, the substrate helps to create a realistic underwater world.

The substrate also conceals waste and junk at the bottom and prevents them from floating around. If you have a planted tank and colorful fish, a dark bottom will provide a stunning contrast.

– Creates a Home for Fish

Some fish species like to dig and forage in the substrate for food, while others like to hide at the bottom.

Fish eggs and fry can easily hide in the substrate to avoid predation and to grow at their own pace. The fry can also feed on the microscopic organisms that hide in the substrate.

How Often You Need to Change Aquarium Substrate?

High-quality substrates are formulated never to be changed, especially because they provide a surface area for bacteria colonization.

Can You Use Various Substrates in the same Fish Tank?

Can You Use Various Substrates in the same Fish Tank?

Can You Use Various Substrates in the same Fish Tank?

The fish and the plants in your aquarium can have varied needs when it comes to the most suitable substrate. Most aquarists first pour in a nutrient layer and then the substrate to promote the growth of plants.

It is possible to use several substrates in one tank, provided you do not mix those with different grain sizes. While substrate with similar grain sizes can be blended, those with different grain sizes will result in a compressed material.

Acrylic glass or stones are commonly used to build terraces that prevent two kinds of substrates from mixing.

What is the Minimum Height of Substrate for Planted Tank?

Whichever substrate you choose for your aquarium, you have to layer it at the proper depth for your plants. It is recommended to observe a minimum depth of 5cm, with the ideal being 7-8cm.

How to Calculate the Amount of Substrate You Need?

The formula to determine the amount of substrate you need is:

(length x width x depth) / 1000 = liters

If your tank measures 80 cm and 30 cm, with the substrate depth being 5 cm, the formula will be:

80 x 30 x 5/1000 = 12 liters, which is about 12 kg depending on the weight of various substrates.

Should You Vacuum the Aquarium Substrate?

Vacuuming is important to get rid of the small particulates in the substrate. Elements like uneaten food and fish waste get sucked away during vacuuming while the substrate stays in place.


Substrates are essential in a planted aquarium, mainly because they provide plants with the necessary nutrients for growth.

Opt for an enriched substrate from reputable brands to ensure that it does not affect the water conditions of your aquarium. You should also get a substrate that is ideal for the kind of plants and fish you keep.

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