Best Aquarium Bio Balls 2024 & Handling Guide

Biological filtration is one of the ways to filter aquarium water, and it uses beneficial bacteria in water purification. The bacteria is the primary agent in breaking down ammonia and nitrate and turning them into less toxic compounds. Like the living organisms in the tank, good bacteria also need to thrive by increasing the oxygen levels in the water and surface areas.

If you’re a serious aquarist, your aquarium should have room for biological filtration. It can sustain an aquarium with a small population of fish. But you need to utilize a combination filtering means if you have a bigger fish tank.

To have effective biological filtration, you need to use the proper type of filtering media. One of the best choices is bio balls, which you can use in freshwater and saltwater fish enclosures. For this discussion, let’s know more about bio balls and determine which ones are the best for your aquarium.

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Green Vista 1.5-inch Bio Balls

Aquatic Experts 1.5-inch Bio Balls

J-star 1-inch Bio Balls


1.5 inch

1.5 inch

1 inch


1000 pieces

300 pieces

50 pieces






100% polypropylene

100% polypropylene

100% polypropylene

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What are bio balls, and how do they work?

If you closely look at an aquarium, you may notice that there are black spheres submerged underwater. Those spheres are called bio balls, and they have tiny holes or compartments where water-filtering bacteria can grow. That’s why many aquarium enthusiasts refer to them as a nitrate factory. Aside from the aquariums, you can also see them in fish ponds, filtering out toxic compounds and transforming them into less harmful nitrates.

Bio balls are effective in a wet-dry filtration system where water flows through them. It’s like they are the rocks that filter a running stream. The moving filtration system provides more oxygen into the holes, which results in better bacterial growth inside the black spheres. Although it’s typical to see them under the water, bio balls shouldn’t stay submerged all the time. They are designed to keep the bacteria wet and the bio balls clean for a longer time.

How bio balls work

There is no specific or standard design for the bio balls. They are available in various designs and sizes, but they all work the same way. They are placed in the aquarium filters in which water flows over the balls. The good bacteria inside the bio balls filter the moving water to remove ammonia and nitrates, clearing the water inside the aquarium.

Ammonia is a by-product of fish wastes, and small amounts of this harmful compound can be lethal to all inhabitants of your aquarium. The bacteria developed inside the bio balls break down the ammonia and turn it into nitrates. Similar to ammonia, nitrites are also toxic to fish and plants. With the help of the good bacteria growing in the balls, nitrites turn into nitrates, which are less harmful to the fish inside the tank.

Benefits of bio balls

Bio balls don’t only aid in biological filtration, and they have other purposes that make them the best filtration media you can use. If you’re a dedicated aquarist, these benefits should encourage you to utilize bio balls as part of your aquarium’s filtration system.

  • The distinct feature of bio balls is their multiple poles that aren’t easily clogged. Water can pass through them and be filtered by the healthy bacteria right away.
  • Using these filter media makes biological filtration straightforward. You’re assured that the aquarium water remains clean for the fish.
  • Because of bio balls, oxygen-rich water can smoothly flow through them, giving the aquarium and healthy bacteria enough oxygenation to sustain life.
  • Bio balls are not exclusive to aquariums, and you can use them in other filtration systems and waterscapes like garden ponds, fish hatcheries, and aquaponics. They also work well in both freshwater and saltwater.

How do I use bio balls?

Let’s say that you already have purchased bio balls and a mesh bag. Put the balls inside the bag, then hang the bag in the stream of water that flows through the filters. Preferably, you set it up at the mouth of a membrane filter to prevent clogging.  Yes, you can also submerge bio balls. But since the balls are effective in a wet-dry filtration system, hanging the bag of bio balls (it’s a trickle-filter setup) will make it conducive for healthy bacteria to grow.

Moreover, the bio balls can catch algae, but remember that they are not meant for physical filtration. You can remove them by hand. Avoid scrubbing the bio balls or using cleaning solvents to clean them. If you do those things, you remove the healthy bacteria that purify the water. If organic growths clog the holes, use your hands to remove them. Make sure that you don’t scrape the balls’ surface and interior.


Bio balls should only be used in a biological filtration system. They are designed to cultivate healthy bacteria that can make the water breathable for the fish. If you misuse them, it can lead to nitrite buildup, which harms the living organisms in the aquarium. Don’t expect them to remove wastes from the water. That’s the purpose of mechanical filtration, like what foam blocks and sponge pads do.

If you wish to utilize biological and mechanical filtration together, you need to set up the automatic filters first before placing the bio balls. The mechanical filters in your filtration system block waste before reaching the bio balls, preventing ammonia and nitrites from spreading in the aquarium. Remove the buildup from the automatic filters from time to time to avoid filter blockage.

How many bio balls do I need for my aquarium?

Apparently, you can’t just use as many bio balls as you want. The amount of bio balls depends on the aquarium setup and probably the brand. However, many hobbyists follow the ratio of 2.2 gallons of bio balls for every 100 gallons of water. If you can fill your aquarium with 50 gallons of water, you’ll need 1.1 gallons of bio balls. The math is pretty straightforward.

Of course, bio balls come in different sizes to be compatible with a range of filter types. If you have a large filter, go with more giant balls for effective biological filtration. But whichever brand of bio balls you buy, make sure to read the instructions or the manual that comes with the packaging. You may add a few more balls than what the instructions recommend, but not too many because it can result in poor water filtration.

The best bio balls in 2024

You already have an idea of what bio-balls are and how to use them. In this part of the article, you’ll know five of the best bio balls in 2024. Each of them has outstanding features, which will help you decide what product is the most appropriate for your aquarium.

1st Aquaneat 1.4-inch Bio Balls


  • Size: 1.4 inch
  • Content: 300 pieces
  • Color: black
  • Material: 100% polypropylene

Starting off this list is the 1.4-inch bio balls by Aquaneat. There are 300 pieces of bio balls in a bag. They are considered as large bio balls, which are ideal for a koi pond or aquarium, freshwater or saltwater fish tanks, garden ponds, fish hatcheries, aquaponics, to name a few. The bio balls have bio-sponges inside the spheres to maximize the cultivation of healthy bacteria within smaller compartments. And because they are made from polypropylene, Aquaneat’s bio-balls are excellent bio-filter media for both freshwater and saltwater fish tanks.

The bio-balls are packed in a mesh bag with a zipper. As soon as you receive the product, you can immediately use the bio balls. They are also easy to use with a fish pond filter, canister filter, or power filter; make sure to read the instructions for proper utilization of the bio filter media. When it’s time for cleaning, all you have to do is unzip the bag and take out the bio balls. You can easily replace the bio balls if you want to replace the bio balls since the mesh bag is reusable. You can reuse the bag several times until it breaks.


  • large bio balls; ideal for big fish tanks and ponds
  • designed with a bio-sponge that can maximize the biological loads within smaller rooms
  • made of 100% polypropylene
  • ready to use
  • comes with a reusable mesh bag


  • can easily get clogged due to the internal sponges
  • bio-sponges make it more difficult to clean
  • not budget-friendly
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2nd Aquatic Experts 1.5-inch Bio Balls


  • Size: 1.5 inch
  • Content: 300 pieces
  • Color: black
  • Material: 100% polypropylene

If you’re looking for bio balls with a one-of-a-kind design, the 1.5-inch bio balls by Aquatic Experts will suit your preference.

Spines surround the balls’ spherical shape, and the unique design maximizes space and allows the balls to fit in any type of filter. The material used to make them is high-density plastic, so you can expect them to be lightweight and durable enough to last a long time. Moreover, these bio-balls are 100% polypropylene, making them reliable filter media for freshwater and saltwater aquariums. They are also multi-purpose; you can use them in water garden ponds, fish hatcheries, and African cichlid tanks.

The Aquatic Experts 1.5-inch bio balls boast of having outstanding filtration. The spines have the perfect placements that expand the surface areas for healthy bacteria to grow. They are also suitable for a trickle-filter system to increase the oxygen level in the aquarium. One pack contains around 300 bio balls, and they are included in a mesh bag that you can set up in your fish tank’s filters. And if you’re worried about cleaning the bio balls, don’t be. You can remove the gunk and other debris by rinsing them in dechlorinated water.


  • unique design using spines for cultivating healthy bacteria
  • can fit it any type of aquarium filter
  • easily cleaned
  • lightweight and durable
  • multi-purpose, safe, and reliable


  • not affordable
  • can easily get clogged
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3rd J-star 1-inch Bio Balls


  • Size: 1 inch
  • Content: 50 pieces
  • Color: black
  • Material: 100% polypropylene

Next on the list is the one-inch bio balls by J-star. They look like Aquaneat’s bio balls, but they are hollow spheres made of plastic. If you open the balls, you’ll see that there is a sponge that makes the filtration more effective. The bio balls have several surface areas or rooms where beneficial bacteria can thrive. They are not big either, so you can easily place them in different types and sizes of filters.

Since they are molded from plastic, the bio balls are lightweight yet tough. They don’t degrade fast, which means that you don’t have to replace them right away. Cleaning the filter media is also straightforward, and you only need to rinse them with water until the filth has been removed. If you choose to purchase this product, it comes in a zip-lock mesh bag with 50 one-inch bio balls. The bio balls also come in 0.62 and 1.41 inches.


  • hollow spheres with sponges inside the balls
  • made of plastic
  • lightweight and tough
  • ready to use and easy to clean
  • comes in a mesh bag


  • doesn’t have a unique structure
  • quite expensive; costs $0.20 per ball
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4th Green Vista 1.5-inch Bio Balls


  • Size: 1.5 inch
  • Content: 1000 pieces
  • Color: black
  • Material: 100% polypropylene

With a diameter of 1.5 inches, the Green Vista Bio Balls are considered jumbo. With the relatively bigger size, the bio-balls feature much higher surface areas for healthy bacteria to propagate. They support the trickle-filter system, boosting the oxygen levels in aquariums, ponds, and other types of waterscapes. What’s more interesting is that the bio balls can combine themselves with the organic waste to clean and filter out the aquarium water.

The design of the Green Vista Bio Balls features spines forming the balls’ spherical structure. The spines significantly increase the surface areas so that more bacteria can grow for better biological filtration. The material used in crafting the bio balls makes them lightweight and durable. They are also flexible, allowing you to use them in various water systems, including hatcheries, wastewater filtration, and cooling filters.

For this option, the package contains around 1000 pieces of 1.5-inch bio balls. It doesn’t include a mesh bag, but it comes with a small bottle of Hydro Bugs Beneficial Bacteria, which is excellent for a newly set up aquarium. These cultured bacteria trigger biological filtration by working with the bio balls in cleaning the water. You may see signs of bacteria colonies after a couple of weeks. And you don’t need to replace them. Even if they look dirty, the Green Vista Bio Balls can still work effectively for a long time.


  • unique design, large size
  • boost oxygen levels
  • can be used in various waterscapes
  • lightweight and durable
  • comes with a bottle of beneficial bacteria


  • doesn’t include a mesh bag
  • quite expensive
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5th Tnfeeon 0.87-inch Bio Balls


  • Size: 0.87 inch
  • Content: N/A
  • Color: blue
  • Material: 100% polypropylene

Completing the list of the best bio balls in 2024 is the Tnfeeon 0.87-inch Bio Balls. Unlike the first four black bio balls mentioned, this batch is a standout due to its light blue color. When it comes to its construction, the Tnfeeon bio balls have multiple holes for the healthy bacteria to grow. But they are also spacious enough for other living organisms to live. Yes, you can submerge these bio balls underwater, and it would be fun to see your fish play with the balls, right?

The blue color is not the only outstanding feature of the Tnfeeon 0.87-inch Bio Balls. They are molded from non-toxic plastic that doesn’t affect the water quality. As previously said, you can put them directly into the water or place them inside a mesh bag, which you can hang on the filter downstream.

These bio balls work well in both freshwater and saltwater, and you can use them with other fish tank accessories. Using the mesh bag included in the package, you can clean the balls every quarter and reuse them, and there is no need for replacements.


  • designed with multiple holes where fish can live
  • come in blue color
  • durable construction
  • can be submerged underwater
  • made of non-toxic plastic
  • good for freshwater and saltwater
  • multi-purpose; can be used in aquariums, fish tanks, garden ponds, hatcheries
  • easily cleaned


  • too visible gunk
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How long does it take for bacteria to grow in bio balls?

The healthy bacteria are not immediately present on the bio balls. If the setup is a new system, it can take a while to develop and stabilize the good bacteria. Fresh aquariums usually take three to six weeks for the nitrogen cycle to successfully transform the toxic compounds. You don’t have to worry about it as long as the other filter media can work properly.

But if your fish tank has already established a stable bacteria population, the growth of healthy bacteria inside the bio balls may not be a long wait. After 14 days, you can already see signs of bacteria forming in the new balls. Sometimes, the growth can be visible in less than 14 days, depending on how healthy your aquarium is.

Do I need to replace bio balls?

The most straightforward answer is: you don’t need to replace the bio balls. They provide a sustainable place where healthy bacteria can thrive. As long as the bio-balls remain clean and are not broken, there is no need for any replacements. If you try to replace the first set of bio balls, you’re removing a healthy part of the biological filtration that can sustain the aquarium.

How do I clean bio balls?

Although replacing bio balls is unnecessary, you may have to clean them when it’s needed. Bio balls get dirty. If you see a thick brown or green filth or sticky substance forming on the balls’ surface, it’s time to clean out the gunk. It’s recommended to do the cleaning when you change the aquarium’s water. But to ensure that nothing is compromised, here are steps that you can follow. It also includes tips for effective bio ball cleaning.

  • The first thing you need to do is prepare a bucket with salt water in it. Use the bucket to wash the bio balls. If you’re changing the aquarium’s water, use the old water to clean the balls. As much as possible, avoid using tap water; it can kill the existing bacteria in the fish tank. If that happens, the aquarium has to do the nitrogen cycle all over again.
  • Turn off the filter and take out the bio balls from the fish tank if you’re all set. Remove a quarter of the bio balls from the chamber first, and then place them inside the bucket filled with saltwater.
  • Stir the water with bio balls to remove the dirt, thick gunk, and other debris that got stuck. If the bio balls are too dirty, repeat this procedure until the dirt comes off. You can do it several times until the filth has come off from the balls. Remember to stir the water only to keep the healthy bacteria or a big part of it. Don’t scrub the bio balls; it can kill the remaining beneficial bacteria.
  • Once you have cleaned the first batch of bio balls, put them back in the filter’s media tray. If possible, don’t clean more than a quarter of the bio balls or all of them at once. Cleaning the bio balls can remove, or worse, kill the healthy bacteria that have built up inside the balls. And cleaning them all at once will remove all the bacteria, leaving your aquarium defenseless against the lethal toxins.
  • After cleaning the bio balls, do an ammonia test to determine the ammonia level present in the aquarium. The test result should be close to or zero. If there is no sign of ammonia a week after cleaning the balls, you can proceed with washing the next batch of bio balls.

Other reminders:

  • Don’t use any cleaning agents like soap, detergent, or disinfectant. They have strong chemicals that easily kill the bacteria on the bio balls and just clean them with water and nothing else.
  • Clean the bio balls once every four months. It retains the efficacy of this filter media. Don’t try to do it every month, even if you notice that bio balls have become so filthy.


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