Buying the perfect substrate for your new planted tank is certainly one of the most complicated and important decisions. It is the main base for any aquarium with good quality natural plants.
The substrate you choose for your planted aquarium not only enhances the visual appeal of your tank, it will also support the overall health of your aquatic plants and animals.
You have to select the right quality of substrate to encourage plant growth and keep the tank free of germs. Your aquarium will be healthy when you choose a quality planted aquarium substrate.
Today ‘s hobbyists have many options before them when it comes to choosing the right aquarium substrate.
Different materials, colors, shapes and sizes of freshwater substrates are available. Gone are the days when sand and gravel were the only types of substrates used in aquariums.
In this article, we’ll tell you about the types of aquarium substrate you can consider for your plant tank and explain why they’ll help the overall health of your indoor plants and animals.
There are two types of plants typically found in freshwater aquariums: those that take root in your substrate and those that grow on your aquarium decor. While all aquatic plants need the right amount of light and nutrients to thrive, your rooting plants need the extra support that a good plant medium can provide.
What is the substrate for a planted aquarium?
However, tank substrate can also have a very noticeable effect on the water chemistry, filtration, and aesthetics of your planted aquarium.
But, it’s not just about buying a good planted aquarium substrate. It is necessary to understand the type of plants you want to keep, as they will tell you the type of substrate for aquarium plants they need.
How to choose the best substrate for a planted aquarium
Before we get into the types of substrate for planted fish tanks, you have to understand some basic notions. Understanding this will allow you to make the right decision for your tank.
The first thing you need to know is how your plants get their food.
- There are plants that obtain most of their nutrients directly from water. That is, they feed on the nutrients dissolved in the water column. This is the case of floating plants.
- On the other hand, there are the plants whose food is carried out through the roots. That is, they are plants that obtain their nutrients from the substrate.
This affects when deciding what type of substrate for aquarium plants to buy.
There is little point in buying an expensive, nutrient-packed planted aquarium substrate if all you have in your tank are plants that feed from the water column.
Benefits of using substrates that improve plants
There are many benefits to using special substrates in your planted tanks instead of using gravel or sand for regular aquariums. Regular aquarium substrates do not provide additional nutrients and trace elements that your plants can use, and the texture and composition of these substrates can impede your plant’s growth.
The size and shape of a plant substrate are carefully calculated to help:
- Protects delicate plant roots
- Support healthy colonies of “good” aquatic bacteria
- Prevent compaction and “oxygen depleted dead zones” from developing
High-quality vegetable substrates also:
- Contains trace elements such as iron and other nutrients to support the health of aquatic plants.
- Slowly releases nutrients over time, preventing ammonia and algae spikes.
- They last for many years and do not need frequent replacement.
- Supports the growth of rooting plants and colonies of good aquarium bacteria
- Particles are sized to prevent oxygen depletion and “dead zones” in your tank
- Provides nutrients and trace elements for healthy plants.
- The fertilizing qualities last for many years before they need to be replaced.
- May be more expensive than traditional aquarium gravels and sand
- Fewer options in terms of colors and textures
- More complicated to use as you may need to add various types of substrate to your tank in layers or pockets to get the effect you want.
- You may still need to add fertilizer and nutrients to the tank to support the plants growing in the décor.
What is the best substrate for a planted aquarium?
Top 5 best substrate for planted aquarium
Below you can see the 5 best-selling substrates for planted aquariums and fish tanks and best considered by expert aquarists.
Gravel larger than 5mm in diameter can cause rooting problems, leading to poor rooting in some plants. This is because the gaps may be too large for the roots to anchor properly.
Conversely, small-grained substrate such as sand will be too compacted for roots to penetrate deeply. Sand beds can also cause anaerobic zones where there is no oxygen. In this way, the flow of water and dissolved nutrients cannot penetrate well.
It is true that some anaerobic areas can be beneficial for the decomposition of nitrates into gaseous nitrogen by anaerobic bacteria.
But be aware that these areas can stop proper root growth if you choose to plant near them.
An ideal grain size for planted aquariums is approximately 2-4mm.
For any rooted plant, let the mulm build up around the base. This will break down and act as a natural fertilizer in planted tanks.
If the plant is large and a great eater, like the Amazonian sword, it is ideal to bury it next to it so that it remains. From there, the accumulated mulm will usually do the rest. Still, use fertilizer if aquarium plants show signs of deficiency.
Best substrates for planted tanks
These six substrates represent some of the best options on the market for planted freshwater tanks that are also compatible with community fish and invertebrates. They are all high-quality products that should help your aquatic plants thrive for years to come.
However, you will still need to use plant fertilizers and other additives such as CO2, especially if you have opted for a densely planted tank or one with plants that cling to your décor. It’s almost always best to allow a planted tank to run for a few weeks before adding animals to your aquarium, in case of ammonia spikes.
1. CARIBSEA ECO COMPLETE COARSE RED
- Weight: 20 pounds
- Type: Full Fortified Gravel
- Red color
- Particle size: coarse from 3 to 6 mm
CaribSea Eco Complete Red is my current favorite when it comes to planted aquariums, and of all the options this might also be one of the easiest to use (along with the other Eco Complete formula below). Coarse red gravel is the perfect size for all types of filtration systems and is easy to vacuum clean.
Your plants will kick into high gear when you add this substrate to your tank, because you won’t have to wait weeks for colonies of good aquatic bacteria to grow. Instead, the bag is filled with proprietary “Amazon” black water along with the substrate. The best part is that there is no need to rinse it, just drop it right into your tank and plant it!
- 3-6mm coarse particle size is ideal for growing rooted aquatic plants and contains 25 essential minerals
- Gravel includes black «Amazonian» water that contains good aquarium bacteria
- No rinsing required so you can add it directly to your tank!
- The bags often break during shipping and can leak the black water that contains the good bacteria.
- Usually a premium priced product and can be expensive for large planted tanks.
- CaribSea recommends not layering or mixing with other products.
2. SEACHEM FLOURITE BLACK CLAY GRAVEL
- Weight: 15.4 pounds
- Type: Full Fortified Gravel
- Particle size: about 2 to 3 mm
For many years, Flourite was my product of choice for planted freshwater tanks. I have used it all alone in densely planted tanks and used it under sand when I wanted a smooth lake bottom look for my aquariums. It is a stable clay-based gravel with high iron content and the ideal size for filtration systems and rooting plants.
Flourite is a high-quality substrate that lasts for years and doesn’t really compact, so you don’t need to worry about dead zones or adding extra gravel to your tank. But it has a big drawback that made me switch to the Eco Complete line: it’s very dirty. It takes forever to rinse and it will still cloud the water.
- 2-3mm porous clay particles are ideal for most rooted plants and support healthy bacterial growth
- Iron and mineral rich clay compound supports healthy plant growth
- It does not compact or break down in your tank and lasts for many years.
It requires additional fertilizers as this formula does not contain everything you need for balanced plant growth.
Clay particles are rough and not ideal for growing plants with fine roots as ground covers.
Very dirty substrate that requires a lot of rinsing and tank cycling
3. FLUVAL PLANT AND SHRIMP STRATUM
- Weight: 8.8 pounds
- Type: Full Fortified Fine Gravel
- Colour: dark brown
- Particle size: about 2mm
If you have a small aquarium with plants and invertebrates, you should consider this special formula for plants and shrimp from Fluval. It is the ideal size and shape for raising baby and adult shrimp, and also works with most filtration systems. You can use it alone or mix it with another substrate if you prefer.
The particles are made from Japanese volcanic soil and molded into a round shape. They provide minerals and iron to your plants and are porous to encourage the growth of aquatic bacteria. Rooting plants of all kinds will thrive in this substrate and it is also safe for most tropical fish.
- Molded soil particles support plant growth and allow adult and baby shrimp to thrive in your tank
- The porous particles help establish good bacteria in the aquarium and keep the pH of your tank between neutral and slightly acidic.
- Round shape is ideal for plants with fine roots or dense growing ground covers
- Soil granules eventually break down and lose their shape, so you may need to replace them every few years.
- Lighter than aquarium gravel, so gravel vacuums and filtration systems can accidentally pick it up
- The change to slightly acidic water pH is ideal for shrimp, but not for all fish and aquatic plants.
4. MR AQUA PLANT SOIL
- Weight: Approximately 1.8 pounds
- Type: Full Fortified Gravel
- Particle size: about 2mm
Another option for a slightly acidic shrimp tank or community tank is this long lasting plant substrate from Mr Aqua. These gravel-sized particles are made of inert, organic materials that slowly release minerals to keep plants and bacteria healthy.
You won’t need to use additional fertilizer for up to 16 months when you use this soil! But there are some disadvantages of the product. It is really ideal for very small tanks and does not come in larger sizes for larger aquariums. Also, this type of substrate will compact and break down and may need to be replaced every few years.
- Ideal size for the cultivation of aquatic plants and the support of invertebrates such as shrimp.
- The organic composition slowly releases fertilizer into the water over 16 months.
- The granules are porous and allow the good bacteria in the aquarium to establish themselves in their substrate
- It is usually quite expensive and is only sold in very small bags.
- The product is not very stable and breaks down over time.
- While the product fertilizes plants for up to 16 months, at some point you’ll need to start adding additional fertilizer to support your plants.
5. UP AQUA SAND FOR AQUATIC PLANTS
- Weight: 11.5 pounds
- Type: Full Reinforced Sand
- Particle size: just under 2mm
If you’ve been considering using Ada soil but don’t mind dealing with the downsides, then this aquarium “sand” for aquatic plants from Up Aqua could be a great choice for your tank. It is not really a sand, but rather small clay-based granules about the size of large sand particles.
They slowly release minerals into the water and help plants grow and thrive. The porous granules also support the growth of healthy bacteria and allow water to flow through the substrate. This is an excellent choice for growing groundcovers with very fine roots and is also gentle enough for loaches.
- Small granules of “sand” slowly release minerals into the water and support the growth of plants and bacteria
- There is no need to rinse, so you can add it directly to your tank.
- The particles are soft enough for delicate fish like loaches.
- The pellets break down over time and can compact, especially in the lower layers.
- The product is buffered so if you have hard water this could raise the pH of the water too much.
- The substrate may discolor and look more gray than black after a few years.
6. CARIBSEA ECO COMPLETE BLACK
- Weight: 20 pounds
- Type: Complete fortified sand and gravel mix
- Particle size: mix from 0.25 to 7 mm
This substrate closely resembles the red Eco Complete, but is black and has a broader mix of particle sizes. But just like the other version, this product is great for planted tanks and all kinds of tropical freshwater fish. Supports lush plant growth and comes filled with “Amazonian” black water for the proliferation of healthy bacteria.
The dense, deep black color will really highlight your plants and fish and the mix of gravel and sand sizes allows plants with delicate roots to thrive. You can easily grow ground covers with this substrate. Like the other CaribSea substrate, you will not have to rinse this product off and you can start planting right away.
- The mix of sand and gravel particles allows a lot of water to flow through the substrate to prevent dead zones.
- Contains 25 minerals proven to support plant growth and comes filled with “Amazonian” black water containing good aquarium bacteria.
- Ready to use right out of the bag, no rinsing required!
- The substrate does not mix well with other types and it is recommended that you do not use this product in layers.
- Substrate contains particles too large for delicate bottom-dwelling fish such as loaches
- Usually a higher priced option and can be quite expensive for larger aquariums.
Types of substrate for planted aquarium
It’s not always easy to immediately identify a good substrate for your tank, because it depends on the type of plants or fish you want to keep. The best substrate for a planted discus tank would be different from African cichlids for example.
This type of substrate for the planted aquarium is the simplest. It does not have any type of nutrient nor does it affect the chemistry of the water. For beginners struggling with water chemistry, it may be your best choice.
The plants used with this type of substrate are certainly limited, since they must be the ones that feed through the water column through the leaves. For example, anubias, ferns, and mosses.
Gravel has always been the most popular aquarium substrate, mostly because of its simplicity. It is an ideal medium for most tanks and for any type of fish.
But in a planted aquarium, gravel can work as long as they don’t produce much waste, and the plants feed from the water column.
Gravel can also be used in the top layer of a fish tank planted with multiple substrates.
Sand is another very common substrate used in many aquariums, especially beginner aquariums.
Sand provides a very natural look in the tank, and when white sand is used, the colors of the plants and fish are brought out dramatically.
For planted aquariums it can be a great substrate as long as coarse sand is chosen.
A type of sand widely used in aquariums is coral sand, which is a substrate made up of crushed corals that slowly dissolve in water.
This coral sand, in addition to decorating the tank, has a chemical function on the aquarium ecosystem. Its dissolution counteracts the acidification of the medium, raising the pH of the water.
The nutrient substrate for aquarium is similar to natural soil, it comes with multiple beneficial nutrients for the development of the plants in your planted fish tank.
This substrate is best suited for planted aquariums. The nutrients provided by the substrate will help the plants develop. And the tight texture will help the roots of the plants, achieving a strong and stable fixation in the substrate.
This type of substrate for aquarium plants is not highly recommended for beginners, since they tend to alter the chemical parameters of the aquarium water.
The ability of these substrates to absorb and retain nutrients causes an alteration of the parameters that balance the water at levels suitable for plants. But these alterations must be taken into account when thinking about having other living beings that are not plants.
There are many varieties of this type of nutritious aquarium plant substrate. However, you should do some research on the various types of nutritious substrate before purchasing the one to use in your tank.
Complete substrates such as ADA aqua soil or CaribSea Eco-Complete contain all the necessary nutrients and are the best substrate for a planted aquarium. The problem is that they are not recommended for beginners.
Complete Aquarium Plant Substrate is excellent for beginning aquarium cycling because it tends to cause a very noticeable ammonia spike.
For this reason, it is advisable to plant “to the full” from the beginning, since otherwise, the explosion of algae will be brutal.
Even so, during the first two months of the aquarium’s life, it will be necessary to do 50% water changes a couple of times a week.
Of course, don’t even think about putting a single fish in until the tank is fully cycled.
This planted aquarium substrate is based on adding a base of sand, a middle layer of nutritious aquarium soil and a final top layer of gravel, mimicking a natural aquatic environment. This type of layering can create a good base for your plants to take root in, and provides a great environment for them to grow.
And by stratifying the substrates, the gravel will help prevent smaller particles from clouding your tank water.
SAND AND FORTIFIED SAND SUBSTRATES
Aquarium sand is usually collected from streams and rivers or manufactured from silica and processed into a uniform size and shape. Any substrate with a particle size of 1/16 to 2 mm in diameter is considered “sand” no matter what it is made of.
Most types of sand are not ideal for growing rooted aquatic plants. While plain black sand in planted tanks can look spectacular and show off your fish, they do not contain any nutrients or trace elements to support your plant growth. Also, sand compacts easily and inhibits good bacterial growth.
Sand tanks almost always have problems with dead zones and produce spindly, weak plants.Plant and shrimp fortified aquarium arenas are the exception to the rule. These products have a small particle size but are not really sand. Especially when layered with another substrate they can produce fantastic results!
GRAVEL AND FORTIFIED GRAVEL SUBSTRATES
A substrate is considered an aquarium gravel if the particle size is 2mm or more in diameter. Aquarium gravels can be collected from nature or artificially made from resins, clay, or even soil. You’ll have to read the fine print to determine what each product is made of, as it’s not always easy to tell.
The best fortified gravel substrates for planted tanks are usually made from natural ingredients and slowly release nutrients and trace elements into your aquarium water. They may contain volcanic ash, iron-rich clay, or other natural ingredients that increase the fertility of the plants in your tank.
Common aquarium gravel and products made from polished pebbles, glass, or resins are not suitable for growing rooting plants. Your plants may be fine for a while, especially if you add fertilizer to the water, but they won’t thrive.
SOILS FOR POTS AND SOIL FOR AQUARIUMS
You may be tempted to make an aquarium out of potting soil, but I would advise against it if you also plan to keep aquatic animals and fish in your tank. While potting soils can provide a decent rooting environment for plants, they quickly fade as soil nutrients are depleted. You will also need to replace the soil frequently.
They are also nearly impossible to vacuum clean and generally do not work with aquarium filtration systems. You can occasionally make it work by using a bag of potting soil under a layer of sand or gravel, but this is not ideal for your plants.If you want to use something like potting soil, why not consider aquarium soil?
Technically, these soils are considered water sands due to their fine particle size and some are labeled sand and soil. An Ada floor aquarium would be an option, or you can search for Controsoil for sale online. Look for products that specifically mention that they support the growth of plants and bacteria and that they are safe for fish.
LATERITE AND VERMICULITE
Laterite is a type of iron-rich porous clay, and vermiculite is a mineral-rich compact substrate containing aluminium, magnesium and iron.
Laterite and vermiculite are common additives to plant aquarium substrates, but are not generally used alone. In the past, the only option was to make our own plant formulas, so we would have to layer or mix them with our base substrates if we wanted a lush planted aquarium.
These days we have complete aquarium substrates available so we are not limited to mixing custom formulas. But you can still mix laterite and vermiculite into your base substrates to increase their potency, or use vermiculite as the bottom layer of the substrate and cover (cap) it with another product to enrich your rooting plants.
Aquarium Substrates to Avoid for Freshwater Planted Tanks
While it may be tempting to opt for another type of natural aquarium substrate like marble or coral, these are poor choices for planted tanks. While you can use crushed coral substrate in freshwater aquariums to help increase the pH of the water, it can be toxic to aquatic plants.
Crushed coral and marble chips increase the hardness of your aquarium water. Most aquatic plants prefer neutral or slightly soft water and do not thrive in very hard water. I would avoid this type of substrate for planted tanks and opt for a mix that best supports the growth of your plant.
Tips to buy the best substrate for a planted aquarium
When selecting a substrate or substrate mix for your tank, consider the following factors as you research your options:
COMPOSITE VS COMPLETE AQUARIUM SUBSTRATES
A complete substrate is one that you can add to your tank and start planting right away.
- You don’t have to mix or layer it in your tank (although you can still choose to do so)
- A complete substrate supports the roots of the plant and provides the minerals they need to grow. All substrates reviewed below are complete products.
A composite aquarium substrate is one that requires the addition of another type to make it viable for growing plants. Common aquarium gravel, vermiculite, and laterite are examples of composite substrates. If you opt for this mix, you will need to pay close attention to how you place or cover your substrates to avoid cloudy water.
APPEARANCE IN THE TANK
Obviously you want to choose a product that will give your tank the look you are after. But you may be attracted to the appearance of a substrate that is not ideal for rooting aquatic plants, such as soft sand or soil. What should you do in those cases?
- You can always go for a fortified version of the substrate you prefer if one is available.
- Consider stashing bags of high quality substrate in sections along the back of your tank and use your preferred substrate at the front. So your plants can grow into the best things, but you’ll only see the pretty parts!
- You can also use a high quality plant substrate for the lower layers of the aquarium substrate and then cover or cap it with a better looking product. But this might not support dense growth of low-growing plants or ground cover.
Particle size is important to your aquatic plants and animals and affects the function of their filtration systems. Some delicate fish like loaches prefer fine sand and gravel that won’t damage their weights, and some shrimp depend on fine sediment for food. If you choose an option with a very small size, you may need to adjust the filter intakes.
PRICE AND QUANTITY NEEDED
Planted tank substrates can be much more expensive per pound than standard aquarium gravels and sand. While you will generally use about a pound of substrate per gallon of water to fill a fish tank, for planted tanks you will often use much more.
You want at least 2 to 3 inches of good substrate for your rooting plants, and you can use even more if you want to create the impression of hills or valleys in your tank. You will want to use about twice as much fine products like sands and fortified soils as they also pack down a lot.
LONGEVITY OF YOUR SUBSTRATE
Should I worry about changing aquarium substrates and how often should I do it? If you choose a high quality complete planted substrate, like the ones featured in the reviews below, you should not need to change your substrates unless you are completely redoing your aquarium.
You may need to add substrate from time to time to replace what has been lost in filters or gravel vacuums. All substrates compact a bit and some types can also break down and break down in your tank. Sand and earth substrates are the worst compaction offenders and organic substrate granules often break down.
Sandy floors and aquariums are more difficult to maintain because gravel vacuums and filters can pick up sediment along with waste products. Covering filter intakes and gravel vacs to prevent this will leave behind more debris, which could harm your fish and plants.
Gravel substrates are easier to maintain and allow more water flow to prevent dead zones. They also tend to be better at supporting colonies of good aquatic bacteria. These substrates also hide debris and debris better, as they are mixed with the gravel. Sand and dirt tanks can often look messy in comparison.
In general, any type of porous substrate with a high C