How Do Bio Balls Work? How To Use Them | Aquascape Addiction

How Do Bio Balls Work? How To Use Them

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This article covers all you need to know about Bio Balls, What they are, how they work, cleaning and the benefits to using to them. If you have questions then chances are this article should answer them for you.

How Do Bio Balls Work? How To Use Them

Biological filtration is absolutely essential for every single aquarium out there. Without it, there would be a huge buildup of ammonia, resulting in the untimely demise of your fish. The best way to go in our opinion is with bio balls.

They are the best biological filtration media out there in our opinion (we have covered our top 7 picks here). You might not know what bio balls are or how they work to rid your tank of ammonia. So, how to use bio balls? This is the main question we are here to answer today, among others.

What Are Bio Balls?

If you did not already know, bio balls are the method in which your aquarium filter engages in biological filtration. This is absolutely essential to the health and wellbeing of all of the inhabitants in your aquarium. In their simplest form, these things are small plastic or rubber balls, very small. They can also come in other shapes such as pads or cubes, but they are usually spherical in shape.

For some reason, bio balls also tend to be either black blue. Bio Balls come with many little ridges and openings built into them for beneficial bacteria to grow. The purpose of bio balls is to house and grow populations of nitrifying bacteria for your aquarium. In essence, bio balls are the filtration media which every fish tank out there needs to have. They are critical to have for any aquarium.

What Do Bio Balls Do?

A Bio ball comes with all of those little ridges and holes which allow the aforementioned nitrifying bacteria to grow inside of them. The point of having beneficial bacteria in your aquarium water filtration unit is to get rid of certain chemicals and toxins in the water. A bio ball helps solve the problem of ammonia and nitrites in the aquarium water.

You see, ammonia is produced by fish waste. There is no fish waste out there which does not produce ammonia. The problem is that even miniscule amounts of ammonia can be extremely deadly to all of the fish, plants, and other inhabitants of the aquarium. The bacteria which can grow inside of bio balls have the purpose of breaking ammonia down.

Now, the ammonia gets broken now by the bacteria into nitrites. Well, nitrites are still very poisonous to fish and plants, but fear not, because these same beneficial bacteria also break down nitrites. Nitrites are broken down into nitrates, which are easily taken care of and are not nearly as harmful to your fish as ammonia or nitrites.

In layman’s terms, they allow the flow of water through them, so when water goes through the filter, it flows past these bacteria, bacteria which get rid of ammonia and nitrites. They are the biological filter of your aquarium which keeps your fish and plants from being poisoned by unwanted naturally occurring compounds (more on how to clean plants over at this article).

How To Clean Bio Balls

Bio balls can get really dirty, so you do need to clean them off every now and again. Let’s just go through some steps and tips for you to follow to effectively clean them.

  • Place saltwater in a big bucket. This is where you will wash the bio balls. If you are doing a water change, you can always use the water right from the aquarium to do this. If possible you should always use saltwater to perform this task, so if your aquarium is freshwater, don’t use the existing aquarium water.

  • You need to turn off the filter now.

  • Remove about ¼ of the bio balls from the filter media chamber in which they sit.

  • Now, stir the bio balls around in the saltwater to remove dirt and stuck on debris. If they are extremely dirty, you might have to repeat this step a couple of times. Keep in mind to only swish them around. By no means should you scrub them.

  • Take the bio balls and scoop them back into the media tray of your filter. Try not to clean more than ¼ of the bio balls at a time. This is because cleaning them does result in the killing or removal of the benefical bacteria needed to filter ammonia out of your aquarium. Cleaning them all at once will get rid of all of the bacteria, thus rendering your aquarium defenseless against ammonia.

  • You need to get an ammonia test kit for the water (you can buy them here). The ammonia levels in the aquarium should be at zero or extremely close to it. If there is no ammonia in the water a week after you washed the bio balls, move on and clean the next quarter.

  • You should do this once every 4 months to ensure the maximum efficacy of the bio balls.

Why Use Bio Balls?

There are a couple of reasons why bio balls are the best thing to use as opposed to other types of filtration media. Let’s quickly go over why they are the best choice to go with.

  • The biggest advantage you with a bio balls is their very large openings are almost impossible to clog. This means that water will always be able to flow past the bacteria, thus being cleaned in the process.

  • Another advantage is that bio balls allow for oxygen rich water to flow through them, thus providing the bacteria as well as your aquarium with a certain amount of aeration and oxygenation.

Cycling The Aquarium

You need to keep in mind that these beneficial bacteria do not just pop up on the bio balls. They aren’t just there all of a sudden. An aquarium needs to go through a several week or even several month long nitrogen cycling process. This will allow the bio balls enough time to build up a healthy population of beneficial bacteria.

If you put your fish into an aquarium before this cycling has been completed, the bio balls will not have built up enough bacteria to deal with the ammonia adequately. In other words, when you get new bio balls, unless you are adding them to pre-existing ones, you will need to let the filter run with the aquarium void of fish for around 5 weeks. However, there are instant nitrogen cycling chemicals and compounds you can use to immediately complete the nitrogen cycling process.


The bottom line is that bio balls are probably your best bet for keeping your aquarium free of ammonia and nitrites. They are easy to use, easy to clean, and they work wonders.