Fluval Stratum vs Eco-Complete – Which is Right for Your Tank?

Estimated read time 12 min read

Fluval Stratum vs Eco-Complete

We decided to review the top two types of substrates through this detailed comparison of Fluval Stratum vs Eco-Complete substrates.

Nothing beats a nicely decorated fish tank with colorful fish, plants, and rocks. And don’t forget that bottom layer of pebbles and gravel.

That bottom layer is known as substrates, aquarium gravel, or live plant gravel. They’re basically any type of loose additions that cover the bottom of your fish tank. This layer provides many benefits to your tank and plants, as well.

By knowing the best two types available on the market, you can decide which type of substrate best meets your needs.



Read on for more information about each substrate’s features, and how they can benefit your water tank.

Fluval Plant and Shrimp Stratum

Fluval Plant and Shrimp Stratum, For Fish Tanks, 4.4 lbs., 12693

Get Fluval Plant and Shrimp Stratum

This type of substrate is best used with freshwater or saltwater fish tanks. It works great with tropical fish, shrimp, and other types of pet fish. Saltwater tanks provide vibrant and bright colors and shades.

The Fluval Stratum substrate comes in an eye-catching, striking coffee-brown color. It contains nutrients that are suitable for live plants.

Stratum aquarium gravel works to motivate strong plant growth in your tank, as well as healthy root growth. Having healthy plants has two benefits: it makes your tank look attractive and healthy, and it makes your fish happy.


CaribSea Eco-Complete 20-Pound Planted Aquarium, Black

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Manufactured by CaribSea Inc., the Eco-Complete Planted Aquarium Substrate is the best choice for fish tanks that contain live freshwater plants. Its granules are black. They always seem to sparkle and shine, giving the tank a remarkably unique and elegant look.

Freshwater tanks are considered less demanding than saltwater tanks. They don’t have a highly regimented care and maintenance routine.

Another excellent benefit of the Eco-Complete substrate is that it promotes healthy plant root growth. Its high-quality, nutrient-rich make-up provides plants and their roots a natural environment to develop and cultivate.

One of the features that make the Eco-Complete substrate stand out from other types of substrates is that its bi-modal. Bi-modal means it contains both fine and large granules. They work together to bring out the best in each other by naturally forming this arrangement once they’re inside the tank.

The smaller grains fall to the bottom. Yet they still appear to gleam and sparkle anytime the light falls on them.

The larger ones remain on the surface of the substrate layer. They add depth and dimension to your fish tank. Both the small and the large, together, provide the tank with an eye-catching feel.

Palmer Aquatics does a great job comparing these two substrates in the video below, check it out.


Both the Stratum and the Eco-Complete substrates are 100% completely natural. They’re free of any chemicals or dyes. They’re also not coated with any superficial layer.

This is why they don’t cause any discoloration when added to your tank. Even if there’s a slightly cloudy look to the water, it dispels as soon as the gravel settles to the bottom.

Even though both are made from volcanic soil, each has its own set of unique components. Let’s check them out.

Fluval Stratum

Fluval Stratum is made from volcanic soil. It provides your plants, fish, and the water a pH-balanced environment that’s biologically ideal.

The Fluval Stratum substrate is made of the volcanic soil found at the foothills of Mount Aso Volcano in Japan. Volcanic soil is excellent for live aquatic plant life. The science behind this is that it contains high amounts of minerals and nutrients.

The mineral-rich volcanic soil in the Fluval Stratum is no exception. These features make the Stratum suitable for promoting neutral to mildly acidic pH balance of the tank.

The Stratum contains magnesium, iron, potassium, sodium, as well as other types of minerals. When plants find a balanced environment, they grow stronger and healthier. They’re happy getting the right amounts of the micronutrients and macronutrients.


The Eco-Complete substrate is made of volcanic basalt soil. It has over 30 major and minor trace elements, as well as several nutrients and minerals.

Some of these include magnesium, iron, potassium, zinc, aluminum, and sodium. They provide the live plants in your tank with a nourishing environment to promote healthy growth and natural development.

These minerals and elements work together to nourish the plants. When plants find a healthy, well-balanced environment, they grow better. Your tank will look attractive, clean, and well-nourished. And you’ll notice your fish will seem calmer and happier.

When you first open the Eco-Complete substrate bag, you’ll find its contents are wet. If it’s the case, then you have pre-cycled substrates on your hand. And that’s how it should be.

Pre-cycled substrates save you time and effort. Just make sure you don’t rinse the Eco-Complete, as you would with other types of substrates.

Rinsing it means you’ll wash away all the helpful bacteria in the Eco-Complete. That’s the exact opposite of what you want for your tank.

If you prefer, you can strain and eliminate the liquid in the Eco-Complete bag when you first open it. Then add the substrate right away to your tank.

As with any new addition to your tank, the water may appear slightly cloudy at first. However, the water will return to its clear, normal self within 24 hours.

Make sure that the water tank filter is working properly. This will help clear the water faster.


Even though all tank gravel has a porous surface, what makes one better than the other is the extent of its permeability.

Fluval Stratum

The Stratum substrate has a porous surface. This provides plant roots enough space to spread out and develop in a healthy, natural way. It also allows them to breathe and grow stronger.


Eco-Complete has one of the most highly porous surfaces of all the substrates. The reason why the surface area is so vital in a tank is that it helps the good bacteria develop and grow.

It goes so far as to provide up to four times more surface area. Still, you have to use the correct amount accordingly with the size of your fish tank.

Plant Nutrition

Not only do substrates look great, but they also provide trace elements and nutrients to boost plant health.

Fluval Stratum

Fluval Stratum contains a fair amount of plant nutrition. If you feel you need to boost their nutrient content, even more, you can use root tabs. These plant supplements will make sure your plants get the important nutrients they need.

Fluval Stratum is known to break down more easily than other types of substrates. It could be one of the reasons why it makes a powdery mess when first introduced to your tank. But once it settles on the bottom, the water becomes clear once again.


Eco-Complete is rich in over 30 types of useful elements and minerals. These ingredients boost plant growth. They also provide your tank with a healthy, natural-looking environment.

Another reason why the Eco-Complete substrate helps with plant growth is that it’s completely natural and fish-friendly.


Now let’s compare the price of each substrate.

Fluval Stratum

The Fluval Plant and Shrimp Stratum costs more than the Eco-Complete Planted Aquarium Substrate. If you have a tank with a small capacity, it’s a good value. However, if your tank is large, you can end up paying a great deal.

It comes in 3 sizes:

  • 4-lb. bags
  • 8-lb. bags
  • 6-lb. bags


The Eco-Complete Stratum costs less than the Fluval Stratum. It’s a smart choice if you have tanks with a large capacity. This substrate comes in only one size: 20-lb. bags.

Next, let’s look at the benefits and drawbacks of each substrate.

Pros and Cons Fluval Stratum


  • Made from volcanic soil
  • Rich in minerals
  • Contains helpful bacteria
  • Boosts healthy plant growth
  • Keeps pH levels balanced
  • Doesn’t cause discoloration in the tank water
  • Free of chemicals or dyes


  • The price is higher than other types of substrates

Pros and Cons Eco Complete


  • Rich in nutrients
  • Contains helpful bacteria
  • Has an extremely porous surface
  • Boosts healthy plant growth
  • Bi-modal
  • Pre-cycled
  • Free of dyes, chemicals, or artificial coatings
  • Cost-effective price


  • Can be a challenge trying to reach a neutral pH balance

What is a Substrate?

The Fluval Plant and Shrimp Stratum and the Eco-Complete Planted Aquarium Substrate are two types of bottom coverings. They’re the first thing that goes into your tank.

This bottom layer has several uses. It also has many benefits, such as maintaining the quality of the water. Substrates also give plant roots a place to take hold of and grow. They also promote the growth of helpful bacteria.

Having a balanced amount of good bacteria means your fish have a healthy environment to live in. It also boosts the quality of the water and the development of your live aquarium plants.

In general, substrates consist of two or more of the following components.

  • Pebbles
  • Marbles
  • Soil
  • Sand
  • Gravel

The Importance of Substrates

For many, substrates serve only an aesthetics purpose. It’s hard for those with little experience in fish tanks to understand just how important that bottom layer of pebbles and sand is. But this layer is what can make or break your tank.

It offers many benefits for the tank, as well as your fish.

Provide a Natural Habitat

Fish are accustomed to sand, pebbles, and gravel being at the bottom of their habitat. Substrates help imitate that natural feeling. This provides your fish with a safe, natural dwelling to live and develop without any inhibitions.

Contain Helpful Bacteria

Even though your tank filter already provides a great deal of the necessary good bacteria, substrates also give a helping hand. They promote the growth of helpful bacteria. At the same time, substrates help to filter out any unwanted bacteria that may harm the water, fish, and plants in the tank.

Substrates also filter toxins from the tank, as well as almost all types of contaminants.

Make Your Tank Look More Attractive

Substrates give your tank an appealing quality. Some are dark in color, ranging from coffee-brown to black, while others are lighter in color.

Regardless of what shade of color substrates come in, they make the color of the plants and fish pop and appear more vibrant.

Substrates balance out the color scheme of your tank. If you have light-colored fish, try putting dark-colored substrates. They’ll make your fish appear brighter in color.

Give Your Plants a Base

Plants need to find a place for their roots to take hold of. This helps strengthen the roots, and ultimately, the entire plant. It also boosts their growth.

Live plants are important for a healthy, pH-balanced fish tank. They help filter out the tank, promote good bacteria, as well as keep the water at a high quality. Substrates provide plants with a great base to help them stay rooted in one place.

Help Many Types of Materials Settle to the Bottom

Similar to plants and their roots, fish feces need a base to settle on. Substrates provide that support base on the bottom to help prevent feces from floating all over the tank.

Fish food is another type of material that easily floats. Substrates provide it with a safe place to fall to. This makes it easy for small fish to get to their food without fear of being pushed aside.

Frequently Asked Questions

Does Fluval stratum break down?

Fluval Stratum is known to break down more easily than other types of substrates. It could be one of the reasons why it makes a powdery mess when first introduced to your tank. But once it settles on the bottom, the water becomes clear once again.

Should you rinse Fluval stratum?

It really depends. I personally don’t rinse it before use, but others recommend that it’s rinsed. In my experience, if it’s rinsed before use it starts to become muddy and is difficult to work with.

Typically you would place stratum in your tank, place your decor add a little bit of water so you can start to add some live plants, then fill the rest of the tank. That said when you fill your tank be sure to protect the stratum with either a plate or a plastic bag.

Can I mix Fluval stratum with gravel?

Stratum is lighter than gravel so if mixed the stratum won’t mix well. However, if used as a base gravel or sand could be used as a cap for the stratum which is a very common thing to see in dirted tanks.

A Final Note

After reading our in-depth comparison of Fluval Stratum vs Eco-Complete substrates, you probably have made your mind as to which one you’re going to buy for your fish tank.

Both kinds are popular and offer various advantages for your fish, plants, and the tank itself. So, choosing one over the other is ultimately going to depend on your personal preference.

Either type you choose, you’re sure to have a healthy, well-balanced, attractive tank. Your fish will thank you!

Further Reading: Be sure to check out our round-up Best Substrate For A Planted Tank and learn which substrates promote the fastest plant growth.

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