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Bio Balls VS Lava Rock

The debate over bio balls vs. lava rock isn’t new. Ever since the market started becoming saturated with different types of filter media, people have been confused about what they should choose.

Any aqua-life enthusiast has been through this dilemma. If you’re going through one too, don’t worry, we’ve all been there.

Today, we will talk about two main types of filter media: Lava rocks and bio balls. While each of these has its individual importance, only you can choose what’s best for you.

However, the right guide can help make the decision much easier. Let’s begin!

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What Is A Filter Media?

Video: “Looking INSIDE Filter Media for Aquariums and Ponds”

Before we move on to the individual types of media filters, let’s start with the basics. To clear the filter media concept, it is a substance that filters or cleans water for usage.

People use it to:

  • Clean water to drink
  • Swim
  • Irrigate
  • Conduct gas and oil operations
  • Manage stormwater
  • For aquaculture, and much more.

There are different types of media filters. They could use sand, foam, shredded tires, peat, anthracite, geotextile fabric, crushed glass, and many other different types of filtering materials.

Filter media works like any other filter you can think of. It physically and mechanically strains any solid particles from the water.

Such waste could include dust, leftover food, sludge, fish feces, pebbles or rock remains, and other larger materials.

As a result, the water that passes through the filter is clean and safe for human and animal consumption. However, you must clean the filter media regularly and keep it clean to avoid build-up.

What Are Bio Balls?

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Bio balls are a unique type of filter media. As their name suggests, they are small plastic balls that help grow beneficial bacteria. These pegged spheres are more than just a filter; they are biological media.

The primary purpose of a bio ball is to hold beneficial bacteria from an aquarium. They have a large surface area that harbors bacteria and allows them to grow. Then, these bacterial colonies do the job of filtering the entire tank.

Since a bio ball doesn’t remove waste products itself, there is a specific way to use it. Ideally, most experts and manufacturers recommend you use these balls after another filter.

Once the water passes through the primary filter, there won’t be any larger particles in the water that could get stuck in the ball’s grooves. Thus, it can do the job of cleaning up the rest of the smaller debris and dust.


  • They have a larger surface area but only take minimum space in the tank.
  • More surface area gives space to more bacteria, which means better filtration.
  • Since these balls are plastic, they last you a very long time, if not forever.
  • It is effortless to clean a bio ball
  • A bio ball is exceptionally lightweight. It makes it easy to clean, carry, and manage.


  • These filters hold nitrifying bacteria only.
  • You need to clean and maintain the balls to avoid build-up.
  • Cleaning should be done regularly and frequently

What Is A Lava Rock?

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Lava rock is an igneous rock forming from a volcano eruption. After the eruption, the molten lava starts to cool and harden. The unique thing about these lava rocks is that they are very porous.

Thanks to this porous structure, lava rocks become great biological filters. They can grow a colony of microorganisms, called periphyton. This colony then breaks down any dirty, smelly elements like hydrogen sulfide in the water.

Lava rock is widely popular as a biological filter for aquariums. These rocks usually carry denitrifying bacteria, which reproduce and improve the quality of your water. They remove nitrates and make water cleaner, most suitable for aquatic life.

When water moves past the rock’s surface, through the tiny holes, the bacteria extract and consume oxygen from the water. This way, they make an aerobic environment.

The denitrifying bacteria consumes all the nitrates and breaks them into nitrogen and oxygen. This way, it extracts all the excess nitrates from the water and pushes forward clean, safe water towards the other end of the rock.


  • Lava rocks are cheap and extremely affordable for almost everyone. (You can get bags full of lava rocks from local hardware stores for around five dollars.)
  • You can also use lava rocks as a substrate.
  • They create a beautiful, aesthetic base for an aquarium.
  • You can also use lava rocks as an alternative to aqua soil and power sand.


  • The holes in lava rocks tend to clog and fill up as well. Thus, it would be best to clean them regularly and avoid build-up.
  • These rocks can be hefty. Thus, it can be tough to handle them, carry them, and wash them so frequently.
  • Lava rocks contain various natural minerals like magnesium and iron. When you put the stone inside the water, it can dramatically affect its pH and make it hard.

Bio Balls Vs. Lava Rock- The Final Verdict

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Overall, bio balls vs. lava rock isn’t a fight; it’s more of a discussion, and everyone has their own perspectives and correct answers. Bio balls are more comfortable to adjust in the tank, and they don’t involve a lot of preparation.

In contrast, lava rocks take a while to prepare. You have to clean them and dry them before you can use them as a filter.

These rocks can also be bulky and require time and effort to remove, clean, and put back. Meanwhile, bio balls take the win in terms of ease and convenience. They are about the same size as lava rock but much lighter and easy to remove.

However, both types of biological filters are small and affordable. They’re both durable and do the job well. Thus, depending on your own preferences and requirements, you can pick one that suits you best.

Aaron Boyd
Aaron Boyd

Hello, I’m Aaron Boyd, the proud owner and author behind Aqua Movement. I hope my article was able to answer your questions. If you want to learn more about me, click the home icon above.

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