What’s The Best Substrate For Betta Fish?

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So you’ve decided to get a betta. Congratulations!

Betta fish are one of the most attractive and rewarding pet fish there are. And naturally, you want to make sure your betta has the best of everything. This even includes finding the best substrate for betta fish.

My recommended betta substrates include

Read on and I will review each and give you my top recommendation!

Why Picking the Right Betta substrate is important

Substrate performs many functions. It provides a medium for you to anchor plants and decor. It is aesthetically pleasing and can set the mood for the whole tank. Substrate even provides a place for beneficial bacteria to live and process harmful ammonia.

Before you go right out and buy any old substrate on the pet store shelf you should ask yourself a few questions.

Do you plan on having live plants or artificial decorations? Do you want a more natural look or do you want something modern that pops? Do you need something that is very easy to clean?

There are a wide array of betta substrates to choose from including sand, gravel, pebbles, and soil. So let’s jump in and take a look at some recommendations!

Best Substrates For Betta Fish

Spectrastone Shallow Creek Regular

This is a great substrate for those of you looking for that natural look. This is natural gravel that varies in color from light tan to dark brown. Each piece of gravel is covered in a natural plant-based coating. This is an inert substrate which means you won’t have to worry about it changing your water pH.

Since it is gravel, tank maintenance can be done without worrying about disturbing the substrate. Lighter substrates have a tendency of being displaced when vacuuming or doing water changes.

I should note that the color and pebble size isn’t always consistent between different bags. Some bags may be lighter in color and grain size bigger or smaller. This is a natural product and some variation should be expected.

This Spectrastone gravel comes in 5-pound bags. Each bag will adequately cover a 5-gallon aquarium. If you have a 10-gallon betta tank you will need two bags.


    • Great natural look
    • Easy to clean and maintain 
    • Natural plant-based polymer coating
    • Won’t affect water pH


  • Pebble size and color isn’t always consistent between bags

Carib Sea Super Natural Moonlight Sand

For those of you who don’t like the rough look of gravel sand is a good option. This CaribSea Super Natural Moonlight Sand is very fine and white in color. It will definitely make your aquarium decor and betta fish stand out!

While this sand is very attractive its fine grain size can be a negative. That’s because it is very easy to disturb. Water flow can easily displace the sand. This includes the water flow from a filter or a water change.

Fortunately, bettas also do not like high water flow. Nothing more than a nice gentle current is not only ideal for your betta but also this aquarium sand.

I would also advise against using this sand in a live planted tank. With plants, you will need more light and with more light, you will get algae. Green or brown algae build-up does not look good on this white substrate.

Overall this is a very attractive substrate you just need to be aware of its downsides.


  • Easily the most attractive sand available
  • White color makes decor and fish stand out
  • Smooth texture will not harm betta fins


  • Easily disturbed and displaced by water current
  • Algae will ruin the nice white appearance

WAYBER Irregular Decorative Crystals

Are you really looking to make a statement with your betta tank? Try these Wayber decorative crystals.

Although it isn’t clearly stated by the company these look to be polished amethyst crystals. I just love the different tones of purple found in amethyst. This will give your betta tank a truly unique appearance.

Being a natural crystal these should not affect the water pH. Just make sure to wash them beforehand. 

The only downside to using this for a substrate is the small 1 pound portion size. You may need 3 bags to adequately cover a 2.5-gallon tank. So unless you have plenty of money to spend I wouldn’t recommend trying to cover an entire 5-10 gallon tank with these.

If you do have a larger tank these would work great to accent a cheaper base substrate like sand or gravel.


  • Polished purple amethyst looks great in a betta tank!
  • Easy to clean
  • Smooth texture will not harm betta fins


  • Small 1 pound bags
  • Expensive to fill a large tank

Carib Sea Eco-Complete

Are you serious about having a live planted betta tank? If so, this CaribSea Eco-Complete substrate is a great choice. This is what I use in my own planted betta tank.

The parent material for this substrate is black volcanic basalt. These basalt grains are very porous and are great at storing nutrients for your plants.

It also comes with over 25 essential minerals which will help your plants flourish. Additionally, it has mycorrhizal symbionts which will help your plants develop strong roots.

It also comes “biologically complete”. This means that it comes with the beneficial bacteria responsible for the aquarium nitrogen cycle. This can make cycling your tank much easier and faster. Because of this it should not be rinsed before use. Doing so will rinse away the included beneficial bacteria

There are a couple of downsides to this substrate. First off, it can cause your pH to increase. So make sure you have a water test kit and check your pH before adding fish.

Overall this is a great substrate for planted betta tanks and I highly recommend it.


  • Great for live aquarium plants
  • Contains 25 essential minerals
  • Comes “biologically complete” for an easy nitrogen cycle
  • Volcanic basalt has great nutrient storage capacity


  • Can increase pH and water hardness

Marina Decorative Gravel

Marina decorative gravel comes in a wide variety of colors. While I prefer the blue gravel it also comes in black, burgundy, neon yellow, orange, and purple.

This is a nice smooth epoxy coated gravel that will not harm your bettas delicate fins. In addition to the texture, the epoxy ensures that this substrate is inert and will not affect your water chemistry. 

As with all substrates, unless otherwise stated by the manufacturer, it’s still best to do a wash before use.

This gravel substrate only comes in 1 pound bags so you may need to purchase multiple bags. Using this in a larger betta tank like may be cost-prohibitive for some people. If you do have a larger tank you can still use this as an accent to a more affordable base substrate.


  • Multiple attractive colors available
  • Smooth inert epoxy coating safe for betta fins


  • Only comes in 1 pound bags
  • Could be cost-prohibitive to fill a larger betta tank

And The Best Substrate For Betta Fish Is…

It all depends! These are all great choices for a betta tank and much of your choice will come down to personal preference. Do you like the look of delicate sand? Would you prefer natural-looking gravel or something with bright artificial colors? Are you set on adding live aquarium plants?

CaribSea Eco Complete planted betta aquarium substrate

As I already stated, in my planted betta tank I use the CaribSea Eco-Complete. Therefore this is what I recommend for those of you who want a planted tank.

For my next betta tank, I am seriously considering the amethyst WAYBER Irregular Decorative Crystals. I just can’t get past their unique flashy look. There are other brightly colored substrates but those are artificially colored.

Of course, I’m going to have to use a smaller tank (5 gal max) because this stuff is just too expensive to fill a 10 gallon.

Read on for some more in-depth info about aquarium substrates.

Types of Aquarium Substrates

Let dive a little deeper into the different types of substrates available. The most common types of substrate are sand, gravel, and planted aquarium substrates. In smaller betta bowl type tanks people will also use marbles and other artificial substrates.

Let’s take a look at each.

Sand Substrate

Sand is a very common low-cost substrate. Natural sands are inert and will not affect your water chemistry. 

Sand is available in colors ranging from nearly white to black. Grain size also varies considerably. You can get very fine sand that is almost a powder such as the CaribSea moonlight sand. On the other end of the spectrum, there are coarse sands that are almost a fine gravel in appearance.

It’s best to avoid any type of playground sand and stick to aquarium sand. Playground sand has a tendency to pack down. This can lead to anaerobic dead zones in the sand which can have a negative impact on your tank.

Sand is also typically easier to clean than gravel. Due to the small grain size fish food and waste will rest on the surface instead of working into the substrate.

A downside to sand is that it is light and can be stirred up and displaced easily. This can happen when cleaning or doing water changes. Sand is also not the best substrate for planted aquariums.

Gravel Substrate

Gravel is a mainstay of the aquarium hobby. It’s cheap, durable and available in a wide variety of colors and sizes.

In addition to natural colors available, there are also a lot of artificially colored gravels on the market. These include all of the basic colors as well as fluorescent colors that glow under black lights. 

Gravel substrates are the easiest substrate to firmly anchor plants and decor in. You also won’t have to worry about stirring up or displacing the gravel when cleaning and doing water changes.

On the flip side, fish food and waste easily become trapped in coarse gravel. More care will need to be taken when cleaning the tank. It takes a bit of work to get all of the debris out. I use a gravel vacuum on my siphon for this when doing water changes.

Gravel vacuum cleaning betta tank substrate

Plants do well in gravel as the coarse grains allow plenty of room for the roots to grow out. Depending upon how demanding the plants are you may need to add root tabs or liquid fertilizer. Gravel does not supply any plant nutrition on its own.

Planted Aquarium Substrates

There are a variety of substrates intended for planted aquariums. These include volcanic basalt, soil, and clay. These substrates are not going to be fancy or flashy but will instead have a nice natural look.

All good planted aquarium substrates have all the essential nutrients your plants will need. Even so, when your substrate gets old or if you have demanding plants you may need to add fertilizer eventually.

These substrates are not inert. Meaning they will affect pH and water hardness to some degree. This is due to things like the humic acid and other minerals in the substrate. It is advised to wait to add your betta until your water parameters have stabilized and the nitrogen cycle is complete.

Other Substrates

In addition to the above-mentioned substrates there are artificial substrates. These can really add some flare to your betta tank. They include marbles, decorative pebbles/crystals, and acrylic accents.

These are almost always more expensive per pound than natural sand or gravel. Due to this, I would only use them in a small betta tank or bowl. Or you can use some to accent a cheaper bland substrate in a larger aquarium.

How much substrate Do I Need For My Betta Tank?

So you have decided on what type of substrate you want for your betta. The next question becomes how much substrate do I need? Not getting the right amount can result in lost time setting up your new tank.

Generally, you need at least 1 inch of substrate in your tank. With a planted tank you will need a depth of 2-3 inches. This will allow adequate depth to anchor plants and decor. 

This is the depth you will need across the bottom of the entire tank. Feel free to create mounds and other features to make the aquascape more interesting.

How many bags do you need to purchase? This is difficult to answer because it varies widely with each type of substrate. When you decide on a substrate make sure to check the recommendations for that specific product.

If anything buy a little extra and return what you don’t need.

Final Thoughts

I hope this article has given you the information you need to make an educated decision. Part of the joy of getting a new betta fish is setting up his new home.

Best of luck!