Best Substrate For Planted Tank – The Key To Awesome Aquascape

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Next to saltwater reef tanks, the most beautiful type of aquariums are those filled with live plants. Planted freshwater tanks pose a challenge, however, because the ideal substrate for your fish may not support your rooting plant’s growth. If you want to exercise your aquatic green thumb you’ll need the best substrate for planted tanks!

Quick Comparisons of the 6 Best Substrate for Planted Tanks

IMAGE BRAND DETAILS
tnk-table__imageCaribSea Eco Complete Coarse Red
  • Weight: 20 pounds
  • Type: Complete Fortified Gravel
  • Color: Red
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tnk-table__imageSeachem Flourite Black Clay Gravel
  • Weight: 15.4 pounds
  • Type: Complete Fortified Gravel
  • Color: Black
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tnk-table__imageFluval Plant and Shrimp Stratum
  • Weight: 8.8 pounds
  • Type: Complete Fortified Fine Gravel
  • Color: Dark Brown
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tnk-table__imageMr Aqua Plant Soil
  • Weight: Approximately 1.8 pounds
  • Type: Complete Fortified Gravel
  • Color: Black
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tnk-table__imageUp Aqua Sand for Aquatic Plants
  • Weight: 11.5 pounds
  • Type: Complete Fortified Sand
  • Color: Black
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tnk-table__imageCaribSea Eco Complete Black
  • Weight: 20 pounds
  • Type: Complete Fortified Sand and Gravel Mix
  • Color: Black
View Product

Introduction to Substrates for Planted Aquariums

There are two types of plants typically found in freshwater aquariums: those that 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 a good plant substrate can provide.

Benefits of Using Plant-Enhancing Substrates

There are many benefits to using special substrates in your planted tanks rather than using regular aquarium gravel or sand. Regular aquarium substrates don’t provide any extra nutrients or trace minerals your plants can use, and the texture and composition of these substrates can actually impede your plant’s growth.

Close up shot of hands putting plants on the low water aquarium.

The size and shape of a plant substrate are carefully calculated to help:

  • Protect delicate plant roots
  • Support healthy colonies of “good” aquatic bacteria
  • Prevent compaction and oxygen-depleted “dead zones” from developing

High-quality plant substrates also:

  • Contain trace minerals like iron and other nutrients to support healthy aquatic plants
  • Slowly release the nutrients over time, preventing ammonia and algae spikes
  • Last for many years and don’t need frequent replacement
Advantages Disadvantages
  • Supports rooting plant growth and colonies of good aquarium bacteria
  • Particles are sized to prevent oxygen depletion and “dead zones” in your tank
  • Provides nutrients and trace minerals for healthy plants
  • Fertilizing qualities last for many years before replacement is needed
  • 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 several types of substrate to your tank in layers or pockets to get the effect you want
  • May still need to add fertilizer and nutrients to the tank to support plants growing on decor

Types of Plant Substrates for Aquariums

Aquarium with cichlids fish from lake malawi

It’s not always easy to immediately identify a good substrate for your tank, because it depends on the types of plants or fish you want to keep. The best substrate for a planted discus tank would be different than one for African cichlids, for instance.

There are many types of substrates on the market, but the best aquarium substrates for planted tanks can be broken down into the following categories:

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 from 1/16 to 2 mm in diameter is considered “sand” no matter what it is made from.

Seachem Laboratories Flourite Black Substrate - 7Kilograms / 15.4 lbs

Most types of sand are not ideal for growing rooting aquatic plants. While plain black sand in planted tanks may look spectacular and show off your fish, they don’t contain nutrients or trace minerals to support your plant’s growth. Also, sand compacts down easily and inhibits good bacterial growth.

Sandy tanks nearly always have problems with dead zones and produce spindly and weak plants. Fortified aquarium sands for plants and shrimp are the exception to the rule. These products have a small particle size but are not truly 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 2 mm or larger in diameter. Aquarium gravels can be harvested from the wild or manufactured artificially from resins, clay, or even soil. You’ll have to read the fine print to determine what each product is made from, as it isn’t always easy to tell.

The best fortified gravel substrates for planted tanks are usually manufactured from natural ingredients and slowly release nutrients and trace minerals into your aquarium water. They may contain volcanic ash, rich iron-infused clay or other natural ingredients that boost the fertility of the plants in your tank.

Best Betta Water Conditioner—Guide and Product Reviews - Aquarium with decorations and bubbles on water.

Regular aquarium gravel and products made from polished pebbles, glass or resins are not suitable for growing rooting plants. Your plants may do OK for a while, especially if you add fertilizers to your water, but they won’t thrive.

Potting Soils and Aquarium Soil

You might be tempted to make a potting soil aquarium, but I’d advise against that if you also plan to keep aquatic animals and fish in your tank. While potting soils can provide a decent environment for rooting plants, they quickly fade as the soil’s nutrients are depleted. You’ll have to replace the soil frequently, too.

They’re also nearly impossible to vacuum clean and usually don’t work with aquarium filtration systems. You can occasionally make it work by using a pocket of potting soil underneath a layer of sand or gravel, but this isn’t ideal for your plants. If you want to use something like potting soil, why not consider aquarium soil instead?

Technically, these soils are considered aquatic sands because of their fine particle size and some are labeled as both sand and soil. An Ada soil aquarium would be one option, or you could search for Controsoil for sale online. Look for products that specifically mention they support plant and bacterial growth and are safe for fish.

Laterite and Vermiculite

Leopard Wrasse in Marine Aquarium Tank

Laterite is a type of porous clay that is rich in iron, and vermiculite is a mineral-rich compact substrate that contains aluminum, magnesium and iron.

Laterite and vermiculite are both common additives to aquarium substrates for plants but are usually not used on their own. Back in the day, the only option was to make our own plant formulations so we’d have to layer or mix these into our base substrates if we wanted a lush planted aquarium.

These days we have complete aquarium substrates available so we’re not limited to mixing custom formulas. But you can still mix laterite and vermiculite into your base substrates to boost their power, or use vermiculite as the bottom layer of 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 bad choices for planted tanks. While you can use crushed coral substrate in freshwater aquariums to help increase your water’s pH, it can be toxic to aquatic plants.

Textured background of crushed coral suitable for titles in horizontal.

Crushed coral and marble chips increase the hardness of your aquarium water. Most aquatic plants prefer neutral or slightly soft water and don’t thrive in very hard water. I’d avoid these types of substrate for planted tanks and opt for a mix that better supports your plant’s growth instead.

Tips to Choosing a Plant Substrate for Your Tank

When selecting a substrate or mix of substrates for your tank, consider the following factors as you research your options:

Complete vs Compound Aquarium Substrates

A complete substrate is one you can just add to your tank and start planting in right away.

  • You don’t have to mix or layer it in your tank (although you still might choose to)
  • A complete substrate supports the plant’s roots and provides the minerals they need to grow. All of the substrates reviewed below are complete products.
Aquarium decoration in beautiful background

A compound aquarium substrate is one that requires the addition of another type to make it viable for growing plants. Regular aquarium gravel, vermiculite and laterite are all examples of compound substrates. If you opt for this mix you’ll have to pay close attention to how you layer or cap your substrates to prevent cloudy water.

Appearance in the Tank

Obviously, you want to pick a product that gives your tank the look you’re aiming for. But you may be drawn to the appearance of a substrate that isn’t ideal for rooting aquatic plants, like a smooth sand or soil. What should you do in those cases?

  • You can always opt for a fortified version of the substrate you prefer if there’s one available.
  • Consider hiding pockets of high-quality substrate in sections along the rear of your tank and using your preferred substrate in the front. Then your plants can grow in the best stuff but you’ll only see the pretty parts!
  • You can also use a high-quality plant substrate for the lower layers in your aquarium substrate and then top or cap it with a better-looking product. But this might not support a dense growth of low-growing plants or ground cover.

Particle Size

Sea sand texture made of shell and stone pieces. Seamless texture

The particle size matters to your plants and aquatic animals and affects the function of your filtration systems. Some delicate fish like loaches prefer fine sand and gravels that won’t damage their barbells and some shrimp rely on fine sediment for feeding. If you choose an option with a very small size you may need to adjust the filter intakes.

Price and Amount Needed

Substrates for planted tanks can be much more expensive per pound than standard aquarium gravels and sand. While you’ll usually use about a pound of substrate per gallon of water to fill a fish tank, for planted tanks you’ll often use a lot 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’ll need to use about double the amount of fine products like fortified sands and soils since they compact down so much, too.

Longevity of Your Substrate

hands of aquarist preparing substrate in aquarium for planting water plants

Should you worry about changing aquarium substrates, and how often would you need to do that? If you pick a high quality complete planted substrate, like those in the reviews below, you should not need to swap out your substrates unless you’re completely redoing your aquarium.

You may need to add substrate occasionally to replace any that’s been lost to filters or gravel vacs. All substrates compact down a bit, and some types also may break down and decompose in your tank. Sand and soil substrates are the worst offenders of compaction and organic substrate pellets often decompose.

Maintenance Issues

Sand and aquarium soils are harder to maintain because gravel vacuums and filters can pick up the sediment along with the waste products. If you cover the filter intakes and gravel vacs to prevent this they will leave more waste behind, which could hurt your fish and plants.

Siphon gravel cleaner tool in the aquarium.

Gravel substrates are easier to maintain and allow more water flow to prevent dead zones. They tend to be better at supporting colonies of good aquatic bacteria too. These substrates also hide the debris and waste better since they blend into the gravel. Sand and soil-based tanks can often look messy by comparison.

Top 6 Substrate for Planted Tank Reviews

These six substrates represent some of the best options on the market for planted freshwater tanks that also support community fish and invertebrates. They are all high-quality products that should help your aquatic plants thrive for years to come.

You’ll still need to use plant fertilizers and other additives like CO2, however, especially if you’ve opted for a densely planted tank or one with plants that attach to your decor. It’s nearly always better to allow a planted tank to cycle for a few weeks before adding animals to your aquarium, in case of ammonia spikes.

1. CaribSea Eco Complete Coarse Red

CaribSea Eco-Complete Red Coarse-Grade Plant Substrate, 20 lbs.
  • Weight: 20 pounds
  • Type: Complete Fortified Gravel
  • Color: Red
  • Particle size: Coarse 3 to 6mm
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CaribSea Eco Complete Red is my current favorite when it comes to planted aquariums, and of all the options this could be one of the easiest to use too (along with the other Eco Complete formula below). The coarse red gravel is perfectly sized for all types of filtration systems and it’s easy to vacuum clean.

Your plants will get a jump-start 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 a patented “Amazon” black water along with the substrate. The best part is you don’t need to rinse it—just put it straight in your tank and plant away!

PROS CONS
  • Coarse 3 to 6mm particle size is ideal for growing rooting aquatic plants and contains 25 essential minerals
  • Gravel includes “Amazon” black water that contains good aquarium bacteria
  • Requires no rinsing so you can add it straight to your tank!
  • The bags often break during shipping and may lose the black water that holds the good bacteria
  • Usually a premium-price product and may be expensive for large Planted tanks
  • CaribSea recommends against layering or mixing this with other products

2. Seachem Flourite Black Clay Gravel

Seachem Laboratories Flourite Black Substrate - 7Kilograms / 15.4 lbs
  • Weight: 15.4 pounds
  • Type: Complete Fortified Gravel
  • Color: Black
  • Particle Size: Approximately 2 to 3mm
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For many years Flourite was my go-to product for planted freshwater tanks. I’ve used it completely on its own in densely planted tanks and used it under the sand when I wanted a smooth lake bottom look to my aquariums. It’s a stable clay-based gravel that’s high in iron 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 down, so you don’t need to worry about dead zones or adding extra gravel to your tank. But it has one big downside that caused me to shift to the Eco Complete line—it’s very dirty. It takes forever to rinse clean and it will still cloud your water.

PROS CONS
  • 2 to 3mm porous clay particles are ideal for most rooting plants and supports healthy bacterial growth
  • Iron and mineral-rich clay compound supports healthy plant growth
  • Does not compact or decompose in your tank and lasts many years
  • Requires additional fertilizers as this formula doesn’t contain everything you need for balanced plant growth
  • Clay particles are rough and not ideal for growing plants with fine roots like ground covers
  • Very dirty substrate that requires a lot of rinsing and tank cycling

3. Fluval Plant and Shrimp Stratum

Fluval Plant and Shrimp Stratum, 8.8 lbs.
  • Weight: 8.8 pounds
  • Type: Complete Fortified Fine Gravel
  • Color: Dark Brown
  • Particle Size: Approximately 2mm
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If you have a small aquarium with plants and invertebrates, then you should consider this special plant and shrimp formula from Fluval. It’s the ideal size and shape for raising baby and adult shrimp, and it works with most types of filtration systems too. You can use it on its own 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 support aquatic bacterial growth. Rooting plants of all types will thrive in this substrate and it’s safe for most tropical fish as well.

PROS CONS
  • Molded soil particles support plant growth and allow baby and adult shrimp to thrive in your tank
  • Porous particles help establish good aquarium bacteria and maintain your tank’s pH at neutral to slightly acidic
  • Round shape is ideal for plants with fine roots or growing dense ground covers
  • Soil pellets eventually breakdown and loses their shape so you may need to replace every few years
  • Lighter than aquarium gravel, so gravel vacs and filtration systems can accidentally pick them up
  • Shift to slightly acidic water pH is ideal for shrimp but not all aquatic fish and plants

4. Mr Aqua Plant Soil

Mr. Aqua N-MAR-066 1 L Fine Pet Habitat Water Plant Soil
  • Weight: Approximately 1.8 pounds
  • Type: Complete Fortified Gravel
  • Color: Black
  • Particle Size: Approximately 2mm
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Another option for a shrimp tank or slightly-acidic community tank is this long-lasting plant substrate from Mr Aqua. These gravel-sized particles are made from organic and inert materials that slowly release minerals to support healthy plants and bacteria.

You won’t need to use additional fertilizers for up to 16 months when you use this soil! But there are some downsides to the product. It’s really ideal for very small tanks and doesn’t come in larger sizes for bigger aquariums. Also, this type of substrate will compact and decompose and may need replacing every few years.

PROS CONS
  • Ideal size for growing aquatic plants and supporting invertebrates like shrimp
  • The organic composition slowly releases fertilizer to your water over 16 months
  • Pellets are porous and allow good aquarium bacteria to become established in your substrate
  • Usually rather expensive and only sold in very small bags
  • Product is not very stable and decomposes over time
  • While product fertilizes plants for up to 16 months at some point you will have to start adding extra fertilizer to support your plants

5. Up Aqua Sand for Aquatic Plants

UP AQUA Sand for Aquatic Plants
  • Weight: 11.5 pounds
  • Type: Complete Fortified Sand
  • Color: Black
  • Particle Size: Just under 2mm
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If you’ve been considering using Ada soil but don’t care to deal with the downsides, then this aquarium “sand” for aquatic plants by Up Aqua could be a great choice for your tank. It isn’t truly a sand but rather small clay-based pellets the size of large sand particles.

They slowly release minerals into your water and help your plants to grow and thrive. The porous pellets also support healthy bacteria growth and allow water to flow through your substrate. This is an excellent option for growing ground covers with very fine roots and is soft enough for loaches too.

PROS CONS
  • Small “sand” pellets slowly release minerals into your water and support plant and bacterial growth
  • No rinsing needed, so you can add it straight to your tank!
  • Particles are soft enough for delicate fish like loaches
  • Pellets will decompose over time and may compact down, especially on the lowest layers
  • Product is buffered, so if you have hard water this could raise your water’s pH too high
  • Substrate can fade in color and look more gray than black after a few years

6. CaribSea Eco Complete Black

CaribSea Eco Complete Black Planted Aquarium Substrate
  • Weight: 20 pounds
  • Type: Complete Fortified Sand and Gravel Mix
  • Color: Black
  • Particle Size: Mix 0.25 to 7mm
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This substrate closely resembles the red-colored Eco Complete but is black and has a wider mix of particle sizes. But like the other version, this product is ideal for planted tanks and all types of tropical freshwater fish. It supports lush plant growth and comes filled with “Amazon” black water for healthy bacteria proliferation.

The rich, dense 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 won’t have to rinse this product and can start planting immediately!

PROS CONS
  • Mix of sand and gravel particles allows plenty of water to flow through your substrate to prevent dead zones
  • Contains 25 minerals proven to support plant growth and comes filled with “Amazon” black water containing good aquarium bacteria
  • Ready to use straight out of the bag, with no rinsing needed!
  • Substrate does not mix well with other types and it’s recommended you don’t use this product in layers
  • Substrate contains particles too big for delicate bottom-dwelling fish like loaches
  • Usually a premium-priced option and can be quite expensive for larger aquariums

Conclusion

Beginner’s Guide to Aquarium Substrate—Sand vs Gravel in Freshwater Tanks - Fish tank and live plants

The best substrate for your planted tank depends on your budget and the types of fish and plants you want to grow. For growing more delicate ground covers and bottom-dwelling shrimp and loaches, finer sand-like substrates are best. But gravel substrates are easier to maintain and work with most filtration systems.

If you are still trying to decide which product is right for your tank:

  • The best overall choice would be the CaribSea Eco Complete Red, with the Flourite and Black Eco Complete being close runner’s up.
  • For planted shrimp tanks, the Fluval Stratum is ideal but the Mr Aqua is also a good option
  • If you prefer a sandy substrate, consider the Up Aqua Aquatic Sand, or use a good plant substrate for the lower layers and cap it with the sand of your choice.

Jen has more than 30 years experience as a biologist, aquarist, and fishkeeper. She is an expert in setting up new tanks and maintaining naturally-planted freshwater habitats, and has experience raising a wide variety of aquatic species.

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