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7 Best Substrates for Planted Tank: Gravel, Sand, Marbles

Best Substrate For Planted Tank

Normally, plants spread their roots in soil or sand in their natural environment. However, in a planted tank or an aquarium, the bottom surface is usually either glass or acrylic and plant roots cannot grow on such material.

Substrates are used in place of soil in aquariums, providing a good anchorage point for the roots as well as providing the required nutrients for healthy growth.

Since it will be inside your tank, it is important to choose the best product so that it does not negatively affect your fish. With that in mind, this article looks at some of the best substrates for planted tanks that you should consider buying.

You can also read other product reviews of substrates for bettaaquarium sand.

IMAGE

​PRODUCT

​FEATURES

Carib Sea 770

1. Carib Sea 770 (Eco-Complete Planted Tank Substrate)

  • Eco complete substrate for freshwater tanks
  • Conditions the water
  • 20-pound packaging
Seachem 3725

2. Seachem 3725 (Porous Clay Gravel Aquarium Substrate)

  • Stable porous clay gravel
  • pH neutral
  • 15.4-pound packaging
Fluval 12695

3. Fluval 12695 (Best Substrate for Planted Shrimp Tank)

  • Lowers the pH; ideal for shrimps and tropical fish
  • Mineral-rich
  • Highly porous
  • Supports the growth of nitrifying bacteria
Mr. Aqua N-MAR-066

4. Mr. Aqua N-MAR-066 (Organic and Inert Planted Tank Substrate)

  • Contains organic and inert ingredients
  • Affordable 1.8-pound bag
  • Lasts up to 18 months
ADA Aqua Soil 104-021

5. ADA Aqua Soil 104-021 (Decomposed Leaf Mulch Planted Tank Substrate)

  • Nutrient-rich; based on decomposed leaf mulch
  • 16-pound packaging with large granules
  • Contains humic acid; lowers pH level
  • Ideal for freshwater tanks
U.P. Aqua UA-560B

6. U.P. Aqua UA-560B (Rinse-Free Planted Tank Substrate)

  • Small, rinse-free round granules
  • Ideal for fresh and saltwater tanks
  • Treats the water to have a pH value of 6.5 – 7
  • 11-pound packaging
Hermit Habitat 82112

7. Hermit Habitat 82112 (Ocean Sand Substrate for Planted Tanks)

  • 100% ocean sand with calcium minerals
  • Blue colored
  • Non-toxic and natural odor neutralizer
  • Affordable

PRODUCT

1. Carib Sea 770

(Eco-Complete Planted Tank Substrate)

Carib Sea 770
  • Eco complete substrate for freshwater tanks
  • Conditions the water
  • 20-pound packaging

2. Seachem 3725

(Porous Clay Gravel Aquarium Substrate)

Seachem 3725
  • Stable porous clay gravel
  • pH neutral
  • 15.4-pound packaging

3. Fluval 12695

(Best Substrate for Planted Shrimp Tank)

Fluval 12695
  • Lowers the pH; ideal for shrimps and tropical fish
  • Mineral-rich
  • Highly porous
  • Supports the growth of nitrifying bacteria

4. Mr. Aqua N-MAR-066

(Organic and Inert Planted Tank Substrate)

Mr. Aqua N-MAR-066
  • Contains organic and inert ingredients
  • Affordable 1.8-pound bag
  • Lasts up to 18 months

5. ADA Aqua Soil 104-021

(Decomposed Leaf Mulch Planted Tank Substrate)

ADA Aqua Soil 104-021
  • Nutrient-rich; based on decomposed leaf mulch
  • 16-pound packaging with large granules
  • Contains humic acid; lowers pH level
  • Ideal for freshwater tanks

6. U.P. Aqua UA-560B

(Rinse-Free Planted Tank Substrate)

U.P. Aqua UA-560B
  • Small, rinse-free round granules
  • Ideal for fresh and saltwater tanks
  • Treats the water to have a pH value of 6.5 – 7
  • 11-pound packaging

7. Hermit Habitat 82112

(Ocean Sand Substrate for Planted Tanks)

Hermit Habitat 82112
  • 100% ocean sand with calcium minerals
  • Blue colored
  • Non-toxic and natural odor neutralizer
  • Affordable

1. Carib Sea 770 – Eco-Complete Planted Tank Substrate

Carib Sea Eco Complete Planted Black Aquarium Substrate
  • Suitable for: Freshwater
  • Weight: 20 pounds

As the name suggests, Carib’s Sea Aquarium product is an eco-complete substrate, which basically means that it is mineralogically and biologically complete.

In terms of minerals, this product consists of volcanic basalt that contains over 30 different elements such as calcium, iron, potassium, and sulfur among many others.

These provide the aquatic plants with all the nutrients required for luxurious growth while also encouraging the impressive coloration of fish.    

To put this into perspective, think of the lush aquatic plant life in areas such as Hawaii and Costa Rica are known for because of their rich volcanic soils. These soils contain the same minerals as this substrate and thus, you should expect such plant growth.

However, these elements might raise the water pH as the loose soil causes some cloudiness at first water fill. On the bright side, the product conditions the water for the fish and requires no rinsing before installation.

Biologically, this substrate contains heterotrophic bacteria that helps break down the fish’s waste into food for the plants. This acts as a biological filter, helping to keep your fish safe.

Additionally, it features Floraspore, which enhances root growth, and has a natural bi-modal grading that places the micro grains deeper for root growth and the larger grains on the upper layer for providing a large surface area for the beneficial bacteria.

Pros:

  • ​Mineralogically and biologically complete
  • Conditions the water
  • Helps break down the fish’s waste into plant food

Cons:

  • Raises the water pH to an alkaline level
  • Causes cloudiness on the water on first use

2. Seachem 3725 – Porous Clay Gravel Aquarium Substrate

Seachem Flourite Black Substrate for Planted Tank
  • Suitable for: All Environments
  • Weight: 15.4 pounds

This substrate comes in the form of stable porous clay gravel that is ideal for planted aquaria, though it can also be used in any aquarium environment.

The Flourite black is not chemically coated in any way, making it a neutral substrate that does not alter the pH level of the water. This means that it retains the neutrality of the water, which is safe for the fish.

In terms of use, this product is most effective when used alone as the tank bed but it can also be mixed with gravel to make it more diverse. However, gravel modifiers such as laterite are not necessary because they can severely discolor the water.

That said, this being a natural product, it may form some cloudiness on first use and may require mechanical filtration to get rid of the suspended particles on the water.

This can be reduced by rinsing the substrate so as to get rid of any dust that might have formed as the clay crumbled while the package was in transit.   

On the bright side, once this clay is laid down, it requires no replacement in the entirety of the fish tank and this makes it one of the best soils for planted tanks.

Pros:

  • Stable porous clay gravel; ideal for fresh and saltwater
  • Does not raise the pH level of the water
  • Can be used alone or with additional gravel

Cons:

  • Requires rinsing before use
  • Makes the water cloudy at first

3. Fluval 12695 – Best Substrate for Planted Shrimp Tank

Fluval Substrate Plant and Shrimp Stratum
  • Suitable for: Freshwater
  • Weight: 17.6 pounds

Fluval’s substrate is quite unique because it creates a neutral to a slightly acidic pH environment in the water, which makes it ideal for shrimp, tropical fish, and some plant species. This makes it the top-rated as well as the best substrate for planted tanks with fish.

Though quite expensive, the product is composed of mineral-rich soils found on the foothills of Mt. Aso Volcano in Japan. Its main characteristic is being highly porous, which allows plant roots to penetrate through easily, stimulating superb growth in freshwater aquariums.

This porosity also supports the growth of beneficial nitrifying bacteria that improve the health of the soil by converting fish waste into food for the plants.

In terms of use, Fluval Stratum’s recommended depth in the fish tank is about 3 – 4 cm deep so that the plant roots can anchor well. Once water is filled above it, it forms some cloudiness but this settles quickly.

Pros:

  • ​Acidifies slightly; ideal for shrimps
  • Mineral rich
  • Highly porous for easy root penetration
  • Supports the growth of nitrifying bacteria

Cons:

  • Relatively expensive
  • Usable only on freshwater tanks

4. Mr. Aqua N-MAR-066 – Organic and Inert Planted Tank Substrate

Mr. Aqua N-MAR-066 Pet Habitat Water Plant Soil
  • Suitable for: Freshwater
  • Weight: 1.8 pounds

Mr. Aqua consists of a unique blend of organic and inert ingredients that create a pH level of about 6.6 – 6.8, creating the ideal environment for aquatic plants as well as tropical fish to thrive.

The product provides a stable anchor point for the roots as they feed on the ingredients to grow the plant. It is fertilized to last for up to 18 months after which it has to be changed so that the plants can get a new set of nutrients for continued growth.

In terms of size, this substrate comes in a small but affordable 1.8-pound bag that covers approximately 12 × 6 inches at 1 inch deep, which is quite a small area.

However, if used, it has a purifying property that cleans the water from stains of driftwood. This makes it one of the best freshwater substrate for planted tanks.

Pros:

  • Organic and inert ingredients; creates a favorable pH of about 6.6 – 6.8 
  • Affordable
  • Cleans the water from stains of driftwood

Cons:

  • Very small quantity
  • Requires to be changed every 18 months

5. ADA Aqua Soil 104-021 – Decomposed Leaf Mulch Planted Tank Substrate

ADA Aqua Soil Amazonia Normal Type
  • Suitable for: Freshwater
  • Weight: 16 pounds

Unlike other volcanic or clay soil based substrates, ADA aqua soil is based on decomposed leaf mulch. This makes it very rich in organic elements and nutrients, which are very good for lush aquatic plant growth.

Decomposed mulch is known to form small granules but this product has large soil granules made by compacting soil lumps, and this makes it perfect for the quick development of plant root structures because they can easily penetrate through.

Additionally, these large granules have an irregular shape that makes them look natural when covered with water on the planted tank bed. 

Since it is highly organic, it has a high humic acid content that may cause some cloudiness in the water. However, in this process, the product helps reduce the pH level and softens the water to make it ideal for plant growth.

These features come at a cost because this product is the most expensive substrate in this review. On the bright side, its features outweigh its cost making it a very good substrate for planted tanks.

Pros:

  • Nutrient-rich organic substrate
  • Large granules encourage quick root growth
  • Reduces the pH level and softens the water

Cons:

  • Expensive
  • Causes cloudiness in the water

6. U.P. Aqua UA-560B – Rinse-Free Planted Tank Substrate

UP Aqua Sand for Aquatic Plants
  • Suitable for: All Environments
  • Weight: 11 pounds

UP Aqua is also relatively expensive but it has some very impressive features to show for it. For starters, it is composed of small rounded granules that do not require rinsing before use and do not create a dust cloud when the tank is filled.

The product can be used on all aquatic environments and treats the water to have a pH value of 6.5 – 7, which is a slight variation between neutral and mildly acidic. Such an environment is ideal for aquatic plant growth, making this the best substrate for planted aquariums.

The substrate’s small granules do not disintegrate easily and this makes it easy to set up the tank for first use as well as reset it after changing the water. Additionally, this longevity ensures that they retain a coarse texture on the tank bed, which looks very good.

Pros:

  • Does not require rinsing before installation
  • Can be used on all aquatic environments
  • Does not disintegrate easily

Cons:

  • Relatively expensive

7. Hermit Habitat 82112 – Ocean Sand Substrate for Planted Tanks

Hermit Habitat Terrarium Sand
  • Suitable for: All Environments
  • Weight: 2 pounds

Hermit Habitat's 82112 is composed of 100% ocean sand that is filled with calcium, which is a very important nutrient for hermit crabs. This explains its name, Hermit Habitat. 

Being composed of blue-coated sand makes it bright in color, and this results in an aquarium that is uniquely colored. This gives you a unique tank bed that is quite different from the popular black soils.

Other than that, the sand very affordable, is non-toxic and is a natural odor neutralizer, which means that it acts as a chemical filter to get rid of the bad smell.

Pros:

  • ​100% ocean sand with calcium
  • Brightly colored
  • Affordable
  • Natural odor sterilizer

Cons:

  • Very small package.
  • Does not have a lot of nutrients for plant growth

How to Buy the Best Substrate for Planted Tank

How to Buy the Best Substrate for Planted Tank

1. Type of substrate

There are plenty of substrates that you can use to layer your planted tank’s bed. The most common ones are:

Gravel: Aquarium gravel is basically composed of smooth shaped rocks that are meant not to hurt the fish. The rocks are available in many shapes, sizes, and colors, enabling you to decorate your tank to suit your preference. However, gravel does not contain beneficial nutrients to plant and is not porous. This means that it cannot support aquatic plants on its own.    

Sand: Sand is also not ideal for plant growth. However, it is ideal for the fish that like to dig up the sand, bury themselves or play around with it. This presents another problem, which is clogging of the mechanical filters regularly due to the suspended sand particles.

Soil-like substrate: This is the best type of substrate for planted aquariums. It has the nutrients to support plant growth and is porous enough to provide a strong anchor point for the plant roots. In terms of color, this type is usually dark colored and can be finer than sand or compacted into soil lumps to have a rock-like appearance.

Marble chippings: Marble chippings contain a lot of calcium carbonate, just like sand, which means they can be used as a sand alternative. However, they are not porous and are much heavier than sand.

Marbles: Marbles are usually very colorful and come as small spherical objects that enable you to decorate your tank in any design. They are ideal for breeding fish tanks because they have large spaces between them that can hide eggs from being eaten by other fish before they hatch. However, these gaps can also be filled with fish food, reducing the area for the growth of beneficial bacteria in the tank. 

Buying Advice: If your primary goal is to grow aquatic plants, you better buy soil-like substrates such as Carib Sea's 770.

However, you can also layer the substrates, for instance with Seachem's 3725​ below ​a marble or sand substrate (like Hermit Habitat's 82112) so as to create a unique, blended environment that is ideal for your fish and plants.

2. Compatibility

Compatibility is all about whether the substrate is suitable for freshwater use or both fresh and saltwater use.

If you have a freshwater tank, ​ensure you buy a freshwater substrate such as Fluval's 12695​ or an all-environment substrate ​like U.P. Aqua's UA-560B​.

For a saltwater tank, you have to buy either a saltwater or an all-environment substrate, with Seachem's 3725 being a perfect example. 

3. Nutrients

Nutrients are important to consider because they are responsible for lush plant growth. Before buying any substrate, ensure that you consider the nutrients that your plants need so that you buy a product with the most appropriate nutrients to suit your needs.

That said, if you want lush vegetative growth in your freshwater tank, ADA Aqua Soil's 104-021 is ideal due to its nutrient-rich organic composition. 

4. pH Level

Different types of plants and fish find different water environments suitable for them. One major factor to consider when it comes to aquatic environments is the water pH level.

Some fish and plants prefer higher pH values, which means that the water has more alkalinity in it. However, most of them thrive well in slightly acidic to neutral water conditions.

Therefore, it is important to find out what your plants and fish ​require in pH level before buying a substrate that will affect the pH balance​. 

That said, ​some plants, tropical fish and shrimps require a slightly acidic environment with a pH of 6-7. This makes U.P. Aqua's UA-560B,​ Fluval's 12695 and Mr. Aqua's N-MAR-066​ some of the best, especially when combining plants with these fish.

FAQs

1. Why do I need a substrate for planted tanks?

The primary reason for having substrates is to support plant growth. Plant roots cannot anchor onto a glass or an acrylic floor. The plant also needs nutrient to grow and these come from the substrate.

Other reasons include providing a medium to digest fish waste and fish food waste into plant food as well as providing a natural environment for the fish while also improving the aesthetic appearance of the aquarium. 

2. How much substrate do I need?

The only recommended quantity that is predetermined is the minimum quantity. The substrate bed is recommended to have a depth of at least 1 inch. You can have any depth thicker than this to suit your preferences.

However, you need to be careful about the active substrates that might affect your water properties, and more so the pH level.

Too much substrate might make your water either too acidic or too basic. Therefore, the more you have, the more you should monitor the water’s pH level to ensure it doesn’t become harmful to the plants or fish.

3. Does the substrate need to be changed?

This depends on the substrate. Some require changing after a certain period of time so as to replenish the nutrients for continued plant growth.

Gravel and soil-like substrates are very long lasting and might not require changing at all. However, as a general rule of thumb, if things are not working, change the formula.

If the plants become unhealthy and the pH levels become hard to manage, change the substrate.

4. Do I need to vacuum the substrate?

With bacteria in the substrate, such as in most soil-like substrates, most waste is broken down to plant food.

However, with substrates such as sand and gravel, it is wise to vacuum the substrate every time you clean the tank so that you can refresh everything.

Vacuuming these substrates will help clear out all the clogging waste so that they can be well aerated for better plant growth.

Conclusion 

​In conclusion, for a purely planted tank, Seachem's 3725 stands out ​because it is suitable for salt and freshwater use, and does not affect the pH level.

However, ​with tropical fish combined, U.P. Aqua's UA-560B is the best substrate for planted tanks because it slightly acidifies the water and is suitable for all aquatic environments.