Information, Filters & media, Freshwater fish

How To Keep Betta Fish Without A Filter (Step-by-step guide)

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by Jason Matthews



Looking to keep betta fish without a filter? Fortunately, betta fish can survive in smaller tanks and bowls without a filtration system, but you need to provide the right tank conditions.

Here’s the approach I used to keep betta fish without a filter successfully.

Choose a Tank

In the wild, bettas live in areas with natural filtration in the rice paddies. Therefore, you need to choose the right tank size to mimic their natural habitat. The minimum size tank size for betta fish is 2.5 gallons. However, the recommended size is at least 5 gallons because betta fish need more swimming space.

In addition, you’ll need this space to add plants that can act as a filter. Remember that water quality declines quickly when there’s no filtration system. Because of this, small tanks are not preferable since it’s hard to maintain the water quality when ammonia, nitrate, and nitrite levels spike.

Set Up the Tank

Before adding the betta fish to your tank, you must ensure the parameters are perfect. Betta fish requires these water conditions:

  • Water with a pH range of 6.5 – 7.5.
  • The ideal temperature should be 75 – 81F (24 – 27°C).

Therefore, you don’t need a heater if you live in an area where the water temperature does not go below 24 degrees. You should monitor the temperature using a thermometer.

Add Plants

[Image by Angie Johnston, Pixabay]

Betta tank filters have several benefits, such as water oxygenation, waste reduction, increased good bacteria, and reduced maintenance. Since you won’t be adding a filter, you’ll need to find alternative ways to manage the natural ecosystem, which is crucial in reducing stress levels and infections among your betta fish.

One of the ways to do this is by adding live plants. These plants ensure that your tank environment has enough oxygen. They act as a natural filter and provide lounging areas for the beta fish to feel more secure when they need to hide and rest.

Some of the live plants you can add to the tank include java fern, anubias, and java moss, which grow well in small tanks.

Add a Substrate and Decorations

Betta fish require an inert substrate. As you set this up, you can use sand, gravel, or smooth glass stones, depending on your preference. However, it would be best if you avoided substrates like aragonite sand because it is made up of calcium carbonate, which increases the pH and hardness of the water in the tank.

This fish species need soft, acidic water; therefore, you should avoid using a substrate that increases the hardness.

Apart from adding live plants, it would help if you also had decorations in your betta aquarium. These can be an ideal hiding spot for your fish species when they need to take a break from swimming in the tank. 

Ensure there are no rough edges on your tank to avoid tearing the fins. Betta fish are highly prone to fin rot and get easily injured if you have sharp or rough rocks in the aquarium.

Put Up Lighting

While this is not a compulsory requirement, you can add lighting to the tank for aesthetics. If you have lighting in the room, this is still enough. The live plants in the tank also need lighting to grow; therefore, you can factor this in.

Select Tank Mates

Generally, betta fish are aggressive. They fight with their mates, especially when they are stressed.

To avoid any problems, it might be better to keep bettas alone. However, if you plan to add other varieties, you’ll need to monitor the tank keenly for a few days. Once you notice any signs of aggression, you should remove the tank mates immediately.

Ensure that you don’t overcrowd the tank. If you do, this will lead to poor quality of life, stress, and eventually death. Some of the tank mates you can get for your betta fish include:

  • Cory Catfish
  • Neon Tetras
  • Ember Tetras
  • Clown Plecos
  • Kuhli Loaches
  • Feeder Guppies
  • Shrimp
  • Snails

Change the Water Frequently

Since you are not using any tank filter, you need to do regular water changes. We recommend a 30%-40% water change every few days in such a tank.

Changing the water partially ensures that the parameters stay consistent. Unless necessary, you should avoid changing the water 100% regularly because it will shock your betta fish which can significantly affect their health.  

It would be best if you did this because the water quality declines faster. Uneaten food and betta waste settle on the substrate, leading to ammonia, nitrite, and nitrate buildup.

When the water becomes contaminated, your betta fish can become sick and experience fin and tail rot. To avoid such challenges, ensure that you remove uneaten food and waste before it settles and starts decaying.

As you do the water changes, you must be careful about the additives you use to treat the tank. For instance, using liquid medication and plant fertilizers can affect water chemistry and quality.

Fortunately, you might not need any external fertilizer to keep the plants healthy. Fish waste can act as fertilizer for your plants.


Betta Fish Without A Filter
[Image by Josh Clifford, Pixabay]

Keeping your fish in an unfiltered tank can be challenging because you need to maintain the water quality. However, if you follow these tips and watch the parameters closely, your bettas can thrive and survive without any problems.

If you have a few bettas in a 5-gallon tank, you won’t need a filtration system if you take the necessary measures to avoid contamination. Once you get an ideal tank, add some live plants, decorations, and lighting, get suitable tank mates, and frequently maintain water quality.

Bettas have an ideal water temperature and pH; ensure that you maintain these levels. You should also change the water to prevent waste buildup that can make your betta fish sick. To be successful, ensure that you test your water regularly to identify any changes in the tank that could affect your betta fish.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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