Comparing Seachem Flourite vs Eco-Complete

Seachem Flourite vs Eco-Complete

Use this detailed comparison of Seachem Flourite vs Eco-Complete to learn about these two types of substrates.

Owning an aquarium is relaxing. It’s also beautiful to look at and gives your home a focal point.

Your fish aquarium won’t be complete without a few main items. You have to have one or more types of fish and a couple of plants.

You’ll also have to have a filter and a layer of tank gravel on the bottom of the aquarium. Today, we’re going to discuss that bottom layer, which many believe to be one of the main components of your tank.

This bottom layer is also known as substrate, or, tank gravel. Besides giving your tank an attractive appearance, this layer does so much more! It gives nutrients to the plants, filters the water, and promotes the growth of good bacteria.



Here are the basics about each type of substrate, its features, and uses.

Seachem Flourite

Seachem Flourite Black Clay Gravel - Stable Porous Natural Planted Aquarium Substrate 15.4 lbs

Get Seachem Flourite

The Seachem Flourite Black substrate is manufactured by Seachem. Seachem’s innovative laboratories were founded by Dr. Leo G. Morin more than 3 decades ago. They’re known for their love of finding state-of-the-art solutions to the various problems facing aquarists.

It’s a stable form of porous clay gravel. This Seachem substrate has been grounded, or, fracted, to offer the best type of tank bed covering.

The Flourite Black is extremely effective when it’s used alone as tank gravel. At the same time, it can be combined with other types of substrates to further boost the quality of your fish tank.

The Seachem Flourite substrate is best used with marine aquariums. Yet it’s also great for all types of freshwater aquariums.

This beautiful-looking substrate comes in a rich, attractive deep shade of charcoal black. It’s free of any chemicals, dyes, or superficial coatings. It’s completely natural.

Flourite aquarium gravel is rich in micro-nutrients and minerals. They work to boost the natural growth and development of your live plants. It also enables the plant roots to spread and grow naturally.

Your fish will also love the Flourite Black substrate. It provides your fish with a safe, natural dwelling to live and develop without any inhibitions. Plus, they’ll love tunneling their way through the clay gravel.


CaribSea Eco-Complete 20-Pound Planted Aquarium, Black

Get Eco-Complete

The Eco-Complete substrate is manufactured by CaribSea Inc. it’s best used with 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.

One of the best features of substrates is that they balance out the colors in the tank. Since the Eco-Complete is dark, it’ll make any light-colored fish appear more dynamic.

This high-quality substrate is highly rich in major and minor trace elements, and many minerals. These minerals and elements work together to nourish the plants, promote healthy growth and natural development.

When plants find a healthy, well-balanced environment, it boosts their growth. Your tank will look attractive, clean, and well-nourished. And your notice your fish will seem calmer and happier.

If you’re having some problems with Eco-Complete check out this video from Jay at The Planted Tank. Jay has some great videos for beginners getting into the planted tanks. His channel has helped me out a great deal – check out the video below.


Each type of substrate is rich in minerals and nutrients to boost plant growth. Substrates can consist of one or more of the following items:

  • Gravel
  • Soil
  • Sand
  • Pebbles
  • Marbles

Seachem Flourite

Seachem Flourite Black Clay Gravel - Stable Porous Natural Planted Aquarium Substrate 15.4 lbs

The Seachem Flourite substrate is made of porous clay gravel. Even though it’s not sand or soil, it’s been broken up to resemble a sand-like consistency.

At the same time, it still retains its light, permeable clay gravel structure. Its high-quality design is best used in aquariums with live, natural plants.

The Flourite substrate does its job of providing the necessary amount of helpful bacteria. This maintains a healthy well-balanced environment for the plants and fish.

One of Flourite substrate’s best features is that it helps filter out any unwanted bacteria that may harm the water, fish, and plants in the tank. This substrate also filters toxins from the tank, as well as almost all types of contaminants.

The Seachem Flourite is pre-washed. Yet the manufacturer recommends that you give it a quick rinse before placing it in your tank. When you rinse it, you’ll remove any traces of residual dust that may be in the bag.

When it’s time to place this substrate in your tank, it’s natural for the water to turn slightly cloudy. The water will clear up as soon as the clay gravel settles on the bottom of the tank.

If you’d prefer to speed up the clarifying process further, try Clarity. It’s one of the most trust-worthy water clarifiers available. It’s suitable for both freshwater and marine tank water.

Another feature that makes the Seachem Flourite substrate one of the best on the market is the innovative mesh bottom found inside the bag. It makes it easier to rinse the clay gravel substrate right inside the bag itself, saving you time and effort.


The Eco-Complete substrate is made of volcanic basalt soil. It has more than 30 useful trace elements, minerals, and nutrients. Some of these include magnesium, iron, potassium, zinc, aluminum, sodium, and many more.

The first time you open the Eco-Complete substrate bag, you’ll notice that the substrate is damp. This is because it’s pre-cycled, which means it’s rich in the good types of bacteria.

This Eco-Complete feature saves you time and effort. Make sure you don’t rinse the Eco-Complete, as you would with other types of substrates. Rinsing it in any way will just wash away the helpful bacteria you need to promote the health of your plants. The good bacteria also keep the water’s pH balance in check.

If you prefer, you can strain the substrate to get rid of any liquid in the bag. After that, add it to your tank as you would with any other type of tank gravel.

Once your Eco-Complete substrate is added to the tank, the water may become unclear. That’s a normal reaction to the gravel settling into the water. It should take less than 24 hours for everything to settle back into place. Then, you’ll notice that the water has become clear once again.

One of the features that make the Eco-Complete substrate distinctive is its innovative bi-modal design. Bi-modal refers to the presence of both large and small granules in the gravel itself.

These different sized tank gravel pebbles have a way of naturally arranging themselves on the bottom of the tank. The small pebbles find their way and settle completely to form the substrate bed of the tank. These tiny granules gleam any time the light shines on them.

The large pebbles tend to float and drift more, rather than settle down in one place. The two different sizes, plus the fact that they sparkle in the light, add an appealing quality to the tank.


Both types have a porous surface, which promotes healthy bacteria and plant growth.

Seachem Flourite

The Flourite substrate is made of clay gravel, which has a porous surface. This provides plant roots enough space to spread out and develop in a healthy, natural way.

Even though the Seachem Flourite has a light, permeable surface, its gravel settles completely on the bottom of the fish tank. it doesn’t float to the top or drift in the water.


Eco-Complete has one of the most highly permeable surfaces of all the substrates. It provides up to four times more surface area than other types of substrates.

The reason why the surface area is so vital in a tank is that it helps the good bacteria develop and grow. It also boosts the development of healthy roots underneath the substrate layer.

Environmental Impact

Both the Seachem Flourite and the Eco-Complete substrates contain all-natural, mineral-rich ingredients.

They don’t cause any discoloration in the tank water because they’re free of dyes and artificial colors. Plus, they don’t contain any chemically-treated coating or outer covering.


The Seachem Flourite Black Sand Substrate and the Eco-Complete Planted Aquarium Substrates both play a major role in keeping both the plants and the fish clean. They also filter out the water from harmful bacteria, toxins, and contaminants

These substrates promote healthy bacteria growth and keep the water’s pH balanced. They also give the tank an attractive look, and make it look terrific!

Plants also love porous substrates because it allows them to spread their roots and take hold of the gravel. Other materials that need a support base to settle on are fish feces and fish food. The substrate layer provides this support and prevents the feces and fish food from drifting around in the water tank.

Since substrates contain high levels of nutrients and minerals, they promote healthy plant growth. When your live plants are healthy, your fish will also be healthy and happy.

Plant Nutrition

A good substrate should be rich in minerals and nutrients to promote healthy plant growth.

Seachem Flourite

The Flourite substrate is rich in minerals and nutrients to keep your plants healthy.

Plants need to find a place for their roots to take hold of. Substrates offer a nice base for the live plants to help strengthen the roots, and ultimately, the entire plant. It also boosts their growth and helps them stay rooted in one place.


Eco-Complete contains a wide variety of healthy elements, nutrients, and minerals. It boosts plant growth, as well as provides the 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.

Water’s pH Balance

It’s better if you keep the water’s pH balance at a neutral 7.0. On average, freshwater aquarium fish require a pH balance of between 6.8 and 7.6.

Seachem Flourite

The Seachem Flourite won’t trickle out any chemicals into the tank water. This substrate is pH neutral, so the pH levels remain constant.


The Eco-Complete substrate will cause the water’s pH balance to drop slightly lower than the basic 7.0. On average, it should be anywhere between 6 and 6.5 pH.

Seachem Flourite Pros and Cons


  • Made from specially fracted porous clay gravel
  • Rich in minerals and micro-nutrients
  • Doesn’t require replacement
  • Boosts healthy plant growth
  • The bag comes with an inner mesh bottom for easy rinsing inside the bag
  • Free of chemicals or dyes


  • May create a thin layer of film on your plants

Eco-Complete Pros and Cons


  • Made from volcanic basalt soil
  • 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


To figure out the cost, check the size of your tank. Then calculate how much substrate you’ll need for an even bedding.

Seachem Flourite

The Seachem Flourite Natural Planted Aquarium Substrate costs slightly higher 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’s only available in a 15.4-lb bag.


The Eco-Complete Stratum is more budget-friendly than the Seachem Flourite. It’s a smart choice if you have tanks with a large capacity. This substrate comes in only one size: 20-lb. bags.

Frequently Asked Questions

Is Seachem Flourite good for plants?

Yes, Flourite aquarium gravel is rich in micro-nutrients and minerals. They work to boost the natural growth and development of your live plants. It also enables the plant roots to spread and grow naturally.

How long does it take Flourite to settle?

Flourite is very dusty and you really need to rinse it a lot. Typically it will clear up in about 2 days. Some cloudiness is normal. You can use filter floss to help remove the cloudiness quickly.

How do you use Flourite substrate?

Ensure to place a bowl or plastic bag over the substrate when adding water to avoid disturbing the fluorite and causing your water to cloud. The bowl or plastic bag will allow the water to flow slowly over the Flourite as you fill your aquarium.

After going through our Seachem Flourite vs. Eco-Complete comparison, you now know everything there is about these two top kinds of substrates on the market. When you have all the necessary information, it’s easy to pick the one that best meets your tank’s needs.Find out more about what makes each type of substrate stand out from the others available on the market.A Final Note

Both types of these tank gravel substrates will make sure the plants in your tank get all the nutrients and minerals they need. They give an appealing look to your tank. Plus, they make the colors of the plants and fish pop with color.

Each type has its advantages and disadvantages. Finding the best one to cover the bottom of your tank depends solely on your personal preference.

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.

Jack Dempsey
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