planted aquarium using the best substrate for planted tanks

Best Substrate for Planted Tanks: Buyer’s Guide

Aquarium owners have a lot of decisions to make when it comes to their tanks. One important choice is finding the best substrate for planted tanks. In this post, we will take a look at what type of substrates are best for planted tanks and which ones you should avoid. We’ll also review some popular brands so that you can compare prices and reviews. Our favorite substrate for planted tanks is ADA Aqua Soil Amazonia 9 Liter Normal Type. All in all, there are many factors to consider when choosing your substrate but hopefully our buyer’s guide will help you find the best one for your needs! Let’s dive in!

Best Substrate for Planted Tanks Options:

What is the best substrate for planted tanks?

If you’re an experienced aquarist looking to max out your aquascape, we recommend ADA Aqua Soil Amazonia 9 Liter Normal Type. It is nutrient-dense and will help your plants have a strong start. However, because of the nutrient density, it is also prone to promoting algae blooms and can take up to 8-weeks to settle out.

If you want a natural-looking tank with a substrate that won’t cause as many initial issues, we love Seachem Flourite Black Clay Gravel – Stable Porous Natural Planted Aquarium Substrate. It is a clay-based option that comes in a variety of colors to match your tank decorations. It doesn’t need to be replaced over time, which is great! But it will need nutrient supplementation as it is an inert substrate.

What is Substrate?

Substrate is a layer of material that sits on top of the fish tank’s base. It can be made from natural or man-made materials. The substrate can range from gravel to sand to dirt to crushed coral. It is how your plants will root in your aquarium. It can also have an effect on the water chemistry, filtration, and aesthetic appeal of your tank, making it a very important choice when setting up your tank. ­­­­­

It is also home to bacteria bio-film and microbes which serve as a food source for shrimp. In the substrate, organic debris breaks down into nutrients that can be used by the plants, creating a happy little ecosystem.

Bare Bottom versus Substrate

A bare-bottom aquarium is an aquarium with no substrate. Pretty straightforward, right? They’re easy to clean compared to planted tanks and just require water changes. There is no substrate to trap uneaten food and fish poop, so the debris goes straight into the filter. If you do see waste building up on the bottom, simply vacuum out the detritus.

Because of their simplicity, we recommend bare-bottom tanks for breeding and quarantine tanks. They’re easy to keep clean which means it is easier to control and maintain water conditions. The downside to bare bottom tanks is aesthetics; they don’t look natural nor are they very pretty to view.

Tanks with substrate at the bottom are much more aesthetically pleasing. The substrate also acts as a home for beneficial bacteria, which is crucial for the proper functioning of the nitrogen cycle in your tank. Many fish species, especially bottom-feeders like Cory cats and loaches, also love interacting with substrate, as it mimics their behavior in the wild. Shrimp also love substrate because it typically slightly lowers the water’s pH which is important in a shrimp tank.

Why Do I Need A Planted Tank Substrate?

Using a planted tank substrate starts your tank off on the right foot. Substrates for planted tanks introduce a lot of nutrients into your tank which is great for plants that draw their nutrients from the substrate (for example, Amazon swords). It will help them grow larger and healthier faster than if they were on a non-planted tank substrate. Non-aquatic plants that you include in your tank, like pothos, also fall into this category. However, if you’re using plants like Java Fern, Anubias, or floating plants that don’t draw directly from the substrate, you’re probably better off being a non-planted tank-specific substrate and spending your money elsewhere.

planted tank with dark substrate

One another thing to keep in mind with planted aquariums – at some point in time, typically 1-2 years, the root-feeding plants will draw out all of the nutrients in the soil. This means that you have to add back minerals and nutrients into the soil if you want to sustain the plants. Root tabs are a good way to do this. This guide to plant fertilizers has a lot of helpful hints for finding the best option for your tank. Alternatively, you can uproot your heavy root feeders and switch over to water column feeding plants for a while.

Understanding Planted Tank Substrates

Let’s explore popular choices available today:

Inert Substrates

Inert surfaces will not alter the chemical composition of your aquarium. They’re also easy to manage. Replanting and shaping is easier with inert options. They do not alter water chemistry which means it will be easier to isolate your water column parameters (and make changes if you need to).

  • Clay-Based: These hard-baked clay substrates are durable and will last for a long period of time. They’re also the simplest planted substrate media to maintain. If you want to put root plants in your aquarium, you’ll need to fertilize this substrate choice.
  • Sand: Another inert option for your tank. In order to use sand in a planted tank, you will need to find a pretty coarse grain size so the plants have something to root around. This makes sand a challenging option in a planted tank.
  • Gravel-Based: Gravel is a very common type of aquarium substrate. Gravel comes in a variety of colors and shapes, does not offer any nutrients to your plant, and will not alter the water chemistry in your tank. Gravel is best used for fish-only tanks or planted tanks with water column feeding plants.

Materialized Substrates

Materialized substrates tend to lower pH and soften water. Examples of this type of substrate include ADA Amazonia, Fluval Stratum, Tropical aquarium soil, and Mr. Aqua aquarium soil. They’re excellent for freshwater shrimp tanks and root-based plant tanks. They’re loaded with nutrients and will help your plants grow.

pH Boosting Substrates​​

As the name suggests, these substrates will impact your pH. Crushed coral is a common example. This can be a great option for fish that require a high pH level like African Cichlids. Both aragonite and calcite-based substrates help to increase your pH consistently, eliminating the need for pH balancing treatments.

However, these substrates are not a great choice for planted tanks. Cichlids are known to be plant destroyers, so an African cichlids tank is not a good option for a planted tank.

Potting Soils versus Aquarium Soil

The right substrate will make a huge difference for your live plants in your aquarium. Some aquarists want to use garden soil for their planted tanks in order to save on the cost of expensive planted tank-specific substrates. While we don’t recommend this route for beginners, it can be done with a lot of experimentation and careful practice.

First, use organic soil. Non-organic soil can kill your fish. Low organic content (10-20%) dirt works best. Avoid soil that is densely packed with clay. An easy test for this is the softball test – if you can mold the dirt into softballs and roll them without them breaking into bits, you have clay-rich soil. If this is the only soil you have available, you could also add peat to break up the clay. Avoid compost-heavy soils (or use very sparingly).

To set up your tank, use organic garden or topsoil as the base substrate. Then, add a sand layer on top to cap the dirt so it doesn’t mix into your tank water.

One word of warning – soil is a non-uniform, non-studied product, so figuring out your tank water parameter issues will be much trickier. One of the benefits of using commercial planted tank substrates is that they are widely studied, so there is a wealth of knowledge around how the soil will impact your water parameters.

​How to Choose the Best Substrate for Planted Tanks

When choosing a tank’s substrate or combination of substrates, keep the following things in mind:

Complete vs Compound Aquarium Substrates

As the name suggests, you can add a complete substrate to your tank and immediately start planting. It does not require mixing or layering. It contains all of the nutrients for your plants and will support the plant’s roots.

Similarly, as the name suggests, a compound aquarium substrate requires you to add a different substrate type to create a viable growing environment for plants. Gravel is an example of a compound substrate. This is a more complicated route and not recommended for beginning aquarists because you will need to figure out how to layer or cap your substrate appropriately so it doesn’t cloud your water.

Appearance

Pick a product that creates a tank aesthetic that you like. The challenge comes in when you want to use a substrate that isn’t ideal for rooting plants, like sand or soil. How should you handle that situation?

You have a number of options. First, some substrates come in fortified versions that make them more suitable for planting. That is the easiest path forward if available.

You could also do a gradient of the substrate, where you hide the planted tank substrate towards the back of your tank and use your aesthetically pleasing substrate in the front. Plant your plants in the rear of the tank. Everyone is happy!

Lastly, you can layer your substrates and use a cap. Use the planted tank substrate as the bottom layer and cap it with a preferred product. However, if you want to create ground cover, this probably won’t work.

Particle Size

Substrates come in different sizes ranging from coarse rocks to fine sand. Particle size can affect your filtration systems. Some fish species prefer certain types of substrate (for example, loaches like fine sand). Smaller-sized particles can clog filtration systems so this is something you will need to account for.

Price and Volume Required

Substrates for planted tanks are typically more expensive than standard aquarium substrates like gravel and sand. The general rule of thumb for calculating the amount of required substrate is one pound of substrate per gallon of water. However, planted substrates often require more (typically double the amount) because they compact down so much. Therefore, for a 20-gallon tank, you will require at least 20-gallons of planted tank substrate, potentially up to 40 pounds depending on your aquascaping plans.

If you’re using rooted plants or trying to create hills and valleys in your aquascape, you want at least 2 to 3 inches of substrate.

Substrate Longevity

Because substrate costs can be pretty expensive, it is important to factor in substrate longevity. Not all substrates will last the same amount of time. Inert substrates like gravel and sand don’t break down nor need to be refreshed or replaced but they also don’t provide any nutritional value for your plants.

Unless you’re using a completely inert substrate, specialty substrates for planted tanks will start to be less nutritional to your plants over time. This will usually take between one to three years before you need to start refreshing substrate or supplementing with root tabs. Additionally, you might need to add substrate to replace substrate that is lost to cleaning (gravel vacuums, etc.). All substrates compact down over time, and organic substrates will often decompose over time.

Required Maintenance

The most challenging aquarium substrates are sand and planted aquarium soils. Gravel vacuums and filters suck up the substrate along with the waste products, so your volume of substate will slowly need to be replaced over time. One workaround is covering filter intakes, but this means more waste will stay in your tank which negates the purpose of cleaning. Sand and plant-based substrates also tend to look messier because they don’t hide waste as well as gravel tanks.

Gravel substrates are the easiest choice over time. Additionally, gravel is excellent at supporting healthy bacterial colonies, which is good for your water parameters. Gravel tanks often look the cleanest because waste blends more easily into gravel.

Best Substrate for Planted Tanks Options

Seachem Flourite Black Clay Gravel – Stable Porous Natural Planted Aquarium Substrate

Seachem Flourite is a clay-based substrate. One of the biggest benefits is that it does not have to be replaced over time. This soil is available in a range of colors and grain types, so you can select the one that complements your desired appearance. It won’t change the chemistry of your tank, making it simpler to maintain.

One disadvantage of Seachem Flourite is that it is not nutrient-dense, like some of the other choices on this list. The benefit is that you’re less likely to have algae problems in the first few months of using the substrate. Because of the sharp corners on this substrate, it is not recommended for bottom-dwelling fish species.

Overall, Seachem Flourite is a beautiful, natural-looking soil for planted aquariums with water column feeding plants.

Features:

  • Porous clay gravel
  • Organic

Pros:

  • Long-lasting
  • Available in variety of colors
  • Doesn’t impact water chemistry

Cons:

  • Can cloud aquarium water at first
  • Sharp corners not great for bottom dwellers

CaribSea Eco-Complete 20-Pound Planted Aquarium, Black

CaribSea Eco-Complete is a great option for planted aquariums. It is easy to use, has a particle size that is compatible with most filtration systems and is easy to vacuum when it gets dirty. It is shipped damp because it contains live bacteria which help to kickstart plant growth and nitrogen cycles when starting a new tank.

Because of this bacteria, don’t rinse the gravel before using it, or else you will wash away all of the good bacteria! 

Features:

  • Contains beneficial bacteria to jumpstart your tank
  • Won’t cloud your water

Pros:

  • Contains 25+ minerals to nourish aquatic plants
  • No rinsing required

Cons:

  • Bags sometimes break during shipping, which results in bacteria loss
  • Expensive for large tanks
  • Not recommended for layering or mixing with other products

Mr. Aqua Fine Pet Habitat Water Plant Soil

Mr Aqua Aquarium Soil is similar to ADA Aquasoil but contains less ammonia. It has a porous, granular structure that allows for water exchange. It will impact your water parameters by softening water and lowering the pH.

It is a good option for a shrimp tank or slightly-acidic community tank. The bag size is ideal for smaller tanks and doesn’t come in larger sizes, so if you have a bigger aquarium, you’re going to need to purchase a lot of bags. Additionally, this substrate will compact and decompose over time and may need replacing every few years.

We think it is an excellent, more affordable alternative to ADA quality soil. It’s difficult to come by locally, but the link I’ve provided above makes it a lot easier to get.

Features:

  • Porous pellets
  • Slowly releases fertilizer to your water over 16 months

Pros:

  • Porous pellets encourage good aquarium bacteria colonies
  • Less ammonia means easier to cycle if just getting started

Cons:

  • Decomposes over time
  • Only available in small bags

ADA Aqua Soil Amazonia 9 Liter Normal Type

This is the most famous planted tank substrate, used by expert aquascapers all over the world. It impacts water chemistry by lowering the hardness and pH levels to make the water slightly acidic. Slightly acidic water is ideal for most plants and fish species.

This substrate contains a lot of ammonia and phosphate. That means it will help your plants grow quickly but the nutrient profile might be excessive, leading to algae outbreaks and cloudy water. To counteract this, you can perform lots of water changes during the 8-week establishment period for this substrate. Some aquarists get around this by doing a planted tank dry start.

This substrate breaks down over time, requiring that you refresh it every 1-2 years. Given the high ammonia content, this can be challenging for adding new substrate to the tank and not triggering nitrogen cycle issues. This is an expensive substrate that we recommend for more experienced aquarium keepers.

Features:

  • Makes aquarium water mildly acidic
  • Requires 8-week establishment period

Pros:

  • Extremely reputable brand and world-known product
  • Nutrient-dense soil for planted tanks

Cons:

  • Expensive
  • High ammonia levels make soil replacement more challenging

Fluval Plant and Shrimp Stratum, For Fish Tanks

Fluval Stratum is a specialty substrate designed for shrimp tanks. Its smooth surface is great for shrimp and soft-bellied bottom-feeders. It’s made of volcanic soil, which is a porous material that can function as the home to lots of helpful bacteria. It contains no synthetic binders or coatings. It naturally lowers the pH of your tank, which is ideal for most freshwater plants and fish species.

This substrate is lightweight and easily sucked up by gravel siphons. Use care when cleaning the gravel bed.

Be gentle with this substrate and try not to place it under heavy rocks or driftwood. This substrate can break easily and is less functional once it breaks.

Features:

  • Natural Volcanic based substrate
  • Specially designed for shrimp tanks

Pros:

  • Creates neutral to mildly acidic pH
  • Promotes natural plant growth

Cons:

  • Lightweight – easy to siphon away when cleaning
  • Will break under light pressure

UP AQUA Sand for Aquatic Plants

Struggling with ADA soil and its high ammonia? UP Aqua Sand might be the right choice for you. These are tiny clay-based pellets that resemble sand grains, so you have the aesthetics of sand and the nutrients of a planted tank substrate.

This “sand” will slowly release minerals into your water, allowing your plants to develop and flourish. The substrate is also porous enough so that healthy bacteria colonize and allows water flow. We like this product for ground covers with fine roots. It is also a good choice for soft-bellied bottom-feeders; they won’t get scratched up with this option.

Features:

  • Small sand-like particle size allows for water flow
  • Porous particles encourage beneficial bacteria

Pros:

  • No rinsing needed
  • Soft particles are excellent for soft-bellied bottom-feeders (loaches, Cory cats, etc.)

Cons:

  • Pellets decompose and pack down over time
  • Fades in color over time

Best Substrate for Planted Tanks: FAQS

How much substrate do I need?

A rule of thumb is to use one to three pounds per gallon in your tank. Your substrate depth doesn’t need to be uniform; in fact, it’s better when you vary the depth in certain areas for more variety in your aquascape.

Does substrate ever need to be changed?

Yes, depending on the type of substrate used, it likely will need to be changed. Inert substrates like sand and gravel can last indefinitely with no changes needed. Some nutrient-rich substrates, like soil, should be refreshed every 1-2 years. Be sure to read the product’s instructions for the best way to care for your chosen substrate.

Do I need to clean/vacuum the substrate?

This depends on the type of substrate you’re using. Inert substrates like sand and gravel can benefit from occasional siphoning to remove excess detritus. Some nutrient-rich substrates may require periodic cleaning with a vacuum or by hand. Always consult the product instructions for the best way to care for your product.

Is sand or gravel better for a planted aquarium? What is the best substrate for planted tanks?

Inert substrates like sand and gravel are great for planted tanks because they don’t affect the pH or water parameters. Some nutrient-rich substrates, like soil, can help your plants grow better, but they also have the potential to change your water’s pH and chemistry. The best choice comes down to your particular tank – tank size, type of plants (water column feeding or rooted), fish species, budget, and appearance preferences. We love the look of sand but appreciate gravel’s ease of cleaning and natural appearance.

Best Substrate for Planted Tanks: Conclusion

There are many important considerations when it comes to choosing your planted tank substrate. Finding the best substrate for planted tanks is an important part of aquarium planning. We hope this guide helps you to get started on the right foot with some of those factors. And if you’re looking for a substrate that we haven’t covered here, let us know and we’ll do our best to find the answer for you. Which substrates have you found to be the most beneficial in your planted aquarium? What’s your favorite type of planted tank substrate? Tell us more in the comments!

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