Betta substrate in aquarium

Best Betta Substrate: Buyer’s Guide

Are you in the market for a substrate for your Betta tank? Perhaps it’s about time to upgrade your betta’s tank?

If so, you’re in luck! In this buyer’s guide, we’ll walk you through the different types of substrates available and help you decide which is the best Betta substrate for your tank. Our favorite Betta substrate is Seachem Fluorite. So whether you’re looking for something that will help keep your water clean or something that will add a little bit of color to your tank, we’ve got you covered. Read on to learn more!

Best Betta Substrate Options:

What is the Best Betta Substrate?

Our favorite Betta tank substrate is Seachem Fluorite. It is different than the other offerings on this list as it is made from baked clay, not sand or gravel. That difference, however, allows it to absorb plant fertilizers added to the water column, making this is an excellent choice if you’re planning on a planted Betta tank. We do recommend rinsing it several times before using though or it will cloud your water for several days.

What is a Fish Tank Substrate?

The substrate of your tank is what you choose to put at the bottom of your tank. It can vary greatly in terms of material, but common options include sand, gravel, soil, or pebbles.

For your Betta tank, you want the substrate to be safe, relaxing, and aesthetically pleasing. Safe because you don’t want it to harm your Betta in any way (e.g. by sharp edges), relaxing because the substrate should be additive to creating a natural, peaceful environment for your fish, and aesthetically pleasing because you’re doing to have look at the tank longterm!

It is important to think through your substrate choice because substrate can affect the water parameters in the tank, influence cleaning decisions, and support plant life if you keep a planted tank.

red betta in planted tank with dark betta substrate

Why Use Substrate in a Betta Tank?

In nature, Bettas thrive in an environment with mud, rock, plant life, and rocks. They flourish in their natural environments. Therefore, when you use substrate, you have the opportunity to make the tank feel more natural to your fish. Bare bottom glass tanks will heighten your Betta’s stress levels whereas gravel, soil, rocks, or sand with a lot of plants will mimic their natural environment.

What Substrate Would Bettas Naturally Have in the Wild?

In the wild, a Betta’s natural substrate is usually a sandy-soil mix that might even contain some peat. However, this might not be the best choice for you as aquarium soil can quickly become messy and cloud the water. To counteract this, some aquarists cap soil with sand or gravel. In other words, sand or gravel sits on top of the soil to keep it tamped down. This approach can be complicated for a new fishkeeper though.

If you’re looking for the simplest Betta substrate, we recommend a sand-only substrate approach. To make the sand more natural, you can add leaf litter like Indian Almond Leaves to leach tannins and color into the water (this resembles their natural habitat). You will need to replenish the leaves every few months once they begin to disintegrate.

What are the Different Types of Aquarium Substrate?

There are several types of aquarium substrate, some of which are inappropriate for a betta tank.


Gravel is the most popular aquarium substrate. Gravel comes in a variety of colors and is widely available from any fish or pet store.

A benefit of gravel is that it stays put on the bottom of the tank. Because of its weight, it is not easily disturbed, unlike sand. This helps keep the water clean and clear. It is also very easy to clean with an aquarium vacuum, adding another point for its cleanliness.

Additionally, the shape, weight, and texture of gravel make it a good choice for rooted plants, as it is easy for them to root and grow.

A downside of gravel is that it can contain sharp edges which can damage your betta’s fins and tail. If you choose a gravel bottom, try to remove any sharper pieces before placing it in your tank.


Sand is another popular aquarium substrate. It is often used in tanks with bottom-dwelling fish because it doesn’t have the sharp edges of gravel that can injure delicate underbellies. Sand is also a popular choice in Betta tanks.

One benefit of aquarium sand is that debris like food waste or fish excrement tends to sit on the top of the sand instead of sinking in the nooks and crannies. This makes it easy for bottom-feeders to consume the leftover food or for you to vacuum out before it causes any water parameter issues.

One warning with sand – “bad” bacteria, which release hydrogen sulfide, can grow and flourish in the gaps between sand grains. Hydrogen sulfide is very unhealthy for your fish. In order to avoid this issue, you will need to regularly and gently swirl the sand to break up any air pockets where bad bacteria is accumulating. However, when you do this regular maintenance, it will temporarily cloud your aquarium water.

Overall, sand is more difficult for aquarium plants to root and anchor too, so we consider sand a less hospitable planted tank substrate.

Coral sand

Coral sand is more like gravel than sand. Coral sand is essentially finely ground coral. It is not recommended for Betta tanks because it will make the pH more alkaline over time. This is the opposite environment than you want to create, as Bettas prefer more acidic waters.

Play sand

Play sand (the kind that kids use in sandpits) should not be used in aquariums. Don’t do it! It can contain bacteria that will cause a bloom of brown algae. Brown algae is bad for your fish and difficult to control.


Marbles can be a good option for your betta. Although you might be thinking about the round marbles of your childhood, aquarium marbles are usually flat and smooth. Similar to gravel, they will have large gaps between them where food and fish waste will eventually deposit, requiring some extra cleaning. Overall, marbles are pretty easy to keep clean.

However, these gaps between marbles are also a favored hiding place of betta fry so this can be beneficial.

Natural river stones

Don’t remove stones or gravel from natural water formations. Although natural, specimens taken directly from the environment often harbor parasites, bacteria, and chemicals, all of which can wreak havoc on your tank.

No substrate

While technically not adding substrate is a substrate choice, your Betta would definitely prefer a tank with a substrate bottom. The advantage of this approach is that bare tanks are extremely easy to keep clean.

Do Bettas Prefer Sand or Gravel?

The choice of substrate is mostly up to personal preference. Sand or gravel can both be used successfully, each with its own benefits and disadvantages.

Think carefully about the pros and cons of different substrates, but in the end, what matters most is that you pick one you like so you are more likely to take care of it properly. Bettas can be happy with either choice.

How Much Betta Substrate Do You Need? 

The answer here depends on your tank set-up. The amount of substrate needed is based on the size of your tank plus your live plant plans.

For a fish-only tank, plan to purchase enough substrate to create a substate layer about one inch deep.

If you’re planning to keep a planted tank with rooted plants, you will need about 2 inches of substrate depth so your plants have enough space for their roots.

Does the Color of Betta Substrate Matter?

It doesn’t really matter to the fish, per se, but it will impact your viewing experience. When selecting a substrate color, pick a color that contrasts your betta. For example, if you have a dark Betta, pick a lighter substrate. And correspondingly, if you have a light Betta, pick a darker substrate. The contrast will help your Betta’s color pop in its surroundings!

Best Betta Substrate Options

Caribsea Super Naturals Aquarium Sand, 20-Pound

If you want to use a sand substrate, CaribSea Super Naturals is an excellent choice. This option is an inert substrate, meaning that it won’t impact your water parameters and will make aquarium maintenance easier. It is a good choice for beginners.

This option has lots of color varieties available, meaning you can get a color that really contrasts nicely with your fish.

As we mentioned before, you will need to rake the sand occasionally to reduce the risk of hydrogen sulfide pockets. It is extremely toxic to your fish so this is something you will need to prioritize.

Overall, sand is harder to clean than gravel. Cleaning sand is not as simple as gravel, where you can just shove the gravel vacuum into the substrate to remove waste. If you do that with sand, you’ll end up removing a lot of your substrate.

In order to clean sand, you’ll need to wave the gravel vacuum tube about an inch above the surface of the sand. This motion will stir up the fish poop into the water so you can vacuum it out.

Finally, if you’re doing a planted tank, sand is a tricky choice. It has no nutrient content and can compact to the point it will stop roots from growing.


  • Natural sand substrate


  • Comes in variety of colors
  • Soft for Betta fins


  • Difficult to clean
  • Challenging substrate for plant growth

Spectrastone Shallow Creek Regular for Freshwater Aquariums

If you’re a total beginner, we recommend starting with gravel for your substrate. Gravel is the most popular aquarium substrate and a superb option for a Betta tank.

This gravel mix includes a mix of different-sized river pebbles and stones, which will give your tank a natural look. Overall, gravel works pretty well at anchoring rooted plants but like sand, it doesn’t provide nutrients so you will need to think through plant fertilizer options.

If you go the gravel route, make sure you purchase a gravel vacuum for cleaning.


  • Natural-looking mix of river stones and pebbles
  • Inert substrate (won’t change water parameters)


  • Easier to clean than sand
  • Good for rooted plant anchoring


  • Requires plant fertilizer as no nutrients provided to plants
  • Requires gravel vacuum for cleaning

Small Black Stones Aquarium Gravel River Rock, Natural Polished Decorative Gravel

If you’re looking for a more consistent color to your gravel, this is a great option. This substrate is pure black, pea-sized gravel. It is great for contrasting with light-colored Bettas.

This gravel is not dyed or painted which is a definite benefit. Over time, painted gravels can leach color into the water, which can be dangerous for your fish.

Just like the other gravels we have discussed, waste will accumulate in the substrate, so you’ll need to purchase a gravel vacuum and get comfortable with shoving it down in the substrate so you can remove any deeply nested waste.


  • Black, pea-sized gravel substrate
  • Natural and unpainted


  • Natural stone introduces no risk of leaching paint
  • Won’t impact water chemistry


  • Requires plant fertilizer as no nutrients provided to plants
  • Requires gravel vacuum for cleaning
  • Only comes in large bag so you might have leftovers with small tank

Seachem Fluorite

This option is slightly different from the other options on the list. Seachem Flourite isn’t sand or gravel but instead is a baked clay that is specifically made for planted tanks. There are minerals in the clay that your live plants will appreciate and feed on.

This substrate is cool because it can absorb liquid plant fertilizers added into the water column. It will absorb the nutrients and then your rooted plants will draw the nutrients directly from the substrate. Pretty cool, huh?

It’s also pH neutral, meaning you won’t experience wild water parameter swings when you use this substrate.

This option stands out relative to other planted tank substrates because it doesn’t need to be replaced every few years.

But, the biggest reason is that other kinds of planted substrate have to be replaced every few years, but Flourite doesn’t. It will continue to absorb nutrients from the water column and transfer them to your plants. It won’t turn into a yucky sludge over time like some other substrates.

The main drawback with this option is that you need to do some pre-rinses before adding it to your tank unless you want a clouded tank for a week or two.


  • Baked clay
  • Can absorb fertilizer from water column


  • Great option for planted tanks
  • Good for lifetime of the tank


  • Requires pre-rinsing or will cloud tank

Betta Substrate: Conclusion

There are many factors to consider when it comes to picking the right substrate for your betta tank. Gravel, sand, and planted tank substrates each have their pros and cons so you’ll need to do some research before deciding which is best for you. We want to hear what type of substrate has worked out well for you in the past! Have any good stories or tips about choosing a Betta tank substrate? Share them with us below!

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