Fish That Dont Need A Filter (Best 9 Species For Your Small Tank Or Bowl)

Are you thinking about setting up an aquarium, but don’t want to deal with a filter? That’s understandable, but it’s hard to find critters that don’t need a filter to thrive.

Keep reading and we’ll go over just how important a filter is, and if there are any fish that don’t need a filter.

Are There Any Fish That Don’t Need A Filter?

You will find many sources claiming that there are fish that don’t need to have any filter. But, this is untrue in the vast majority of cases.

A filter is a wonderful tool for keeping your aquarium clean and healthy. It’s difficult to keep an aquarium clean enough without a filter.

Because of this, we don’t recommend keeping any fish without one.

If you want to keep an aquarium without a filter, we’d recommend sticking with shrimp or snails. They are two critters that can stay happy and healthy in a filterless tank.


If you keep a shrimp-only tank, then the little creatures can do well without a filter. Still, they need lots of oxygen, so you should only attempt this if you keep their tank heavily planted.

Shrimp are a great choice. They create less bio-waste than fish and come in many beautiful colors.


Snails are pretty hardy animals that may survive in a tank without a filter. Often, people will create a small planted aquarium with a variety of shrimp and snails.

There are plenty of snail types to choose from, and they make a good tank mate for shrimp.

The Walstad Aquarium

Diana Walstad wrote The Ecology of the Planted Aquarium. Her book is backed by years of scientific research. She has created an effective method of maintaining an almost completely self-sustaining aquarium.

These aquariums need plants, specific layers of substrate, and light. It can be quite difficult to put together a Walstad aquarium. It needs to be just right to be healthy for your fish. For this reason, we only recommend it for more experienced aquarists.

Still, it can be done, and the result is a beautiful tank.

Hardy Fish That May Survive Without A Filter

We’ll reiterate that ALL these fish will be healthier and live longer if you give them a filter. But, this list includes hardier fish that are more likely to survive without one.

To keep your fish healthy without a filter, you’ll need to clean your tank much more often than you would with one.

Betta Fish

Bettas are beautiful fish that come in all different varieties of colors and fin shapes. A healthy betta will often live between three and five years of age.

Bettas are tropical fish that like warm water, so you should provide them with a heater. They also need a tank that is at least five gallons. Bettas are more aggressive than other fish. But, you can often keep them with other species successfully.


Guppies are also popular because of their flowy fins and beautiful coloration.

Guppies are livebearers who do best in groups of one male for every two females. They are a good option for people who like energetic fish that flit around the tank.


Gouramis are the cousins of betta fish and they are just as beautiful. Their bodies are more robust, but they come in a variety of sizes and colors.

Like bettas, the males may become territorial toward each other. So, you shouldn’t house more than one male together. But, they are quite peaceful towards females and other species of fish.


Corydoras are catfish that make a nice addition to any freshwater aquarium. They are easygoing and will help keep your tank clean. They like to eat leftover food from the substrate.

Corydoras stay on the smaller side and come in a variety of different patterns. They prefer to stay at the bottom of the tank. But, you’ll frequently see them darting about amongst the rocks and decorations.


Danios are one of the hardiest freshwater fish. In fact, many people use them as starter fish for their “fish-in” tank cycle because they’re so hardy. They can tolerate just about any water conditions.

They are peaceful fish that make great additions to any community tank. They come in a variety of interesting patterns. They are fun little fish to watch because they have lots of energy. You will always see them swimming around the top and middle of the tank.


Tetras can be a hit or miss. Some are hardier than others, and the more sensitive species won’t do well in a tank without a filter. For example, we wouldn’t recommend getting ember tetras or neon tetras. But, varieties like serpae tetras might make a good choice.

Tetras are a good choice for community tanks because they’re active and colorful. They are schooling fish, so there is always lots of activity in the tank to watch.

White Cloud Mountain Minnows

White cloud mountain minnows are another one of the hardiest species. They can tolerate a variety of conditions and don’t even need a heater.

They are active fish that are interesting to watch. Just keep in mind that they aren’t the most colorful species.

Can Goldfish Live Without A Filter?

Goldfish are one of the fish that absolutely need a filter. You may see others claiming otherwise. But, a good quality filter is essential for goldfish.

Goldfish have very fast metabolisms. So, they are always producing waste, and they produce a lot of it. It can be hard to keep a goldfish tank clean even with a filter, let alone without one.

If you try to keep goldfish without a filter, the water quality is going to decline quickly. Your fish probably won’t live very long.


We really don’t recommend keeping any fish without a filter. Filters are amazing for keeping your aquarium clean and healthy.

If you want an aquarium without a filter, try out the Walstad method. It’s really the only way to keep a healthy aquarium without a filter.

But, if you do decide to set up a regular aquarium without a filter, make sure to keep on top of cleaning and pick hardy fish.

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