How to Choose the Best Aquarium Substrate for Your Planted Tank

hands of aquarist planting water plant hygrophila in new freshwater aquarium

When you’re setting up a new tank, you need the right aquarium substrate to get things going. But which one should you choose?

For an aquarium to thrive for a long time, the right substrate is important. This can make all the difference in your success with maintaining a planted aquarium.

If you’re not sure where to start choosing a planted aquarium substrate, don’t fret. In this guide, we’ll show you exactly what you need to know to make the right decision. Read on to learn more!

Why Use an Aquarium Substrate?

If you’re just getting started, you might not be sure why substrates are necessary, or what they even are. Let’s take a look at why this is an important component of your aquarium setup.

The substrate is simply the material that you put on the bottom of your tank. It doesn’t only serve a decorative purpose – it’s essential for the occupants of your tank to thrive. Here are some of the top reasons why.

1. Starts the Nitrogen Cycle

When you add a substrate to your aquarium, a colony of good bacteria will start to grow on it, sparking the nitrogen cycle.

These bacteria grow all over your tank, but most of them will reside on the substrate. If you want to grow a planted tank, the substrate also provides a place for them to take root. Certain substrates are even designed to offer nutrition that will help plants grow.

In fact, without a substrate, you can’t grow a planted tank. Plants need material to take root in and draw nutrition from.

2. Provides a Natural Environment

An aquarium substrate also provides an environment for fish that’s closer to their natural environment.

If you decide to keep bottom-dwelling fish, they’ll prefer a deeper layer of substrate to mimic their natural habitat. However, all fishes will be calmer and happier when their tank has a layer of substrate.

3. Beautifies Your Tank

In addition to helping your tank to succeed, the right substrate also makes your tank more attractive.

Many people love keeping aquariums because of the lovely aesthetics they offer. You can boost that visual appeal with a substrate that offers both form and function.

In an aquarium, you’re basically recreating an environment that’s found in nature. Substrates help you do that.

Types of Substrates

Now let’s take a look at the different types of substrates you can choose from, and when it’s best to use each one.

1. Gravel

Gravel is a very popular aquarium substrate choice. You’ll see it used in most pet shop aquariums, since it’s both inexpensive and effective.

Gravel is also versatile – it works for any kind of aquarium. And yes, you can grow some plants on it – more about that below.

You can choose from a variety of sizes, shapes, and colors for your tank’s gravel. The only reason some people might not use gravel is that it’s not always the prettiest option. However, for price and versatility, you can’t beat it.

Just make sure the gravel you choose is treated for aquarium use before you add it to your tank.

2. Sand

Sand is another one of the most popular substrate materials. If you are keeping fishes that like to burrow, they’ll love sand.

You can buy ordinary play sand in bulk to use in your aquarium – just make sure to treat it first. You can do this by washing it several times until the water is no longer cloudy, or by boiling it to get rid of harmful bacteria.

3. Coral

Crushed coral is a somewhat less common substrate material.

Coral tends to raise the pH levels of the water in the tank, so it’s a good choice if you’re keeping species that prefer more alkaline water.

4. River Rock

Some people use river rock as either a supplement to gravel or as a substrate material on its own.

These are often used for aesthetic reasons. They’re found in many natural habitats, so they can give a beautiful natural look to an aquarium.

5. Marbles

Marbles, on the other hand, are a completely unnatural look but can offer a cool aesthetic feel to your planted tank.

You can choose marbles in any color scheme to get the look you want.

Marbles are also a good choice if you’re breeding fish that lay their eggs in scattered sites. The eggs will lay between the marbles, so the other fish won’t be able to eat them.

6. Soil

Commercial soil is a must for any planted aquarium.

Live plants need nutrition, which they draw from the soil. It also provides them with a place to anchor their roots.

Commercial soils can look very nice in your aquarium, and you can use additives if you need to add more nutrition to them later.

Choosing the Right Substrate

Some of the materials listed above, like gravel, might seem like they’d never work for a planted aquarium.

However, most planted aquariums do best with layers of at least two different kinds of aquarium substrate. You’ll always want soil to be the first layer – as mentioned above, plants can’t live without it.

On top of the soil, use a second layer, like sand or gravel, to keep the nutrients in the soil and keep the plants from washing away. The lower layer should be high enough to cover the roots of the plant, while the top layer can be about two inches.

The top layer you choose will depend on the look you want, and the kind of creatures you’re keeping. The soil you choose, however, needs to offer the right kind of nutrition for your plants, with no harmful chemicals.

Look for soil substrates that are specifically designed for planted tanks. These will offer the right balance of nutrients that are released over a long time. You should also check to be sure the soil is safe for the other inhabitants of your tank.

Ready to Build Your Planted Tank?

Once you know what to look for, it’s time to set up your planted tank!

Need more tips on how to get an aquarium going? Check out this article on aquarium setup.