Fish that don t need a filter top remarkable species for your tankFish that don’t need filter are typically hardy species. They can withstand inadequate habitats for long periods. Still, you would require ample experience to pull off an aquarium without a filter. Keep reading to learn about these fish that can live without a filter.

Fish that don’t need filter Why they are the best options
Hardy fish They can tolerate a wide range of water conditions.
Small fish They do not produce a lot of waste in their tank.
Cold water fish Some cold water species can tolerate inadequate water quality for extended periods and do not need heaters to survive.

List of Best Fish That Don’t Need Filter

  • Hardy fish
  • Small fish
  • Cold water fish

What Fish Don’t Need a Filter?

Some fish don’t require a filter to survive even though it is a significant tank equipment. Here are the top three fish categories that do not need a filter in their aquarium:

1. Hardy Fish

Hardy fish are the first option because they survive tough habitat conditions. Furthermore, they are not prone to diseases, do not require rigorous care, and are barely affected by temperature changes. While keeping these fish, you do not need to bother much about their habitat requirement. Hence, they are a good option if you consider keeping fish that don’t need a filter.

2. Small Fish

Another great option for fish that don’t need filters is small fish. The less waste the fish produce, the less water it requires and less the probability of needing a filter. Moreover, with small fish, you can opt to keep them in a fishbowl and pour out the water manually. So, the size of the fish plays a key role when looking for fish that don’t need a filter.

3. Coldwater Fish

Some cold water hardy fish can also survive without filters. They also do not require heaters, which are crucial to some fish in captivity.

Furthermore, even though some fish can live without filters, please do not keep them in poor quality water for extended periods as they can become ill. Clean water is important for every fish, so you should not ignore regular water changes.

– Fish Species That Don’t Need a Filter

Indisputably, we have classified the fish that don’t need a filter into categories. But, let’s get to know extensively different fish species that can survive without a filter! Below are a few of them.

  • Betta Fish

Here are some important details you should know about the betta fish species. The betta fish would survive without a filter. With proper care information, they are easy to care for and ideal for all fish keepers’ levels.

Also, they are usually aggressive, but some are more hostile than others. They thrive and remain happy when in their territory but require a warm water habitat of about 77F.

  •  Guppies

Guppies are hardy fish species. They are sometimes referred to as rainbow fish due to their beautiful color and iridescence. These species are peaceful and would get along with other small-sized fish. However, it’s best to keep the same gender together, or they would reproduce at an alarmingly rapid rate.

  •  Endler Guppies

The Endler is a guppies species from Venezuela. These peaceful livebearing fish enjoys planted habitats and are top to middle dwellers. Also, they have a unique sleeping pattern where they fall asleep while at the top of the tank but sink to the bottom. These species are small-sized and would not need a filter, especially in a big tank.

  • Paradise Fish

Like the betta fish, the paradise fish are aggressive and territorial, but they thrive in cooler temperatures. They are hardy and would tolerate acidic habitat of 5.8 to 8.0. So, you do not need an aquarium heater and filter in their tank.

  • White Cloud Minnows

The white cloud minnows are hardy freshwater fish that don’t need a filter or heater. They thrive in temperature setting that ranges from 64F to 72 F and enjoys a pH range of 6.8-7.5. Also, they can live in small groups and require at least 10-gallon tanks.

The white cloud minnows are originally from China and have a gorgeous coloration. They are low maintenance and have a lifespan of up to seven years. Likewise, they can withstand inconsistency in water quality.

  • Zebra Danios

The zebra danios are low-maintenance species, so you do not need to break the bank to keep them. They are small-sized and hardy fish with black and silver zebra-like markings. Also, they do not mind being in a group of other danios.

The zebra danios would typically live for three years if properly cared for. But, they need a lot of hiding places to feel secure. Nonetheless, these fish don’t need a filter, especially in a big tank.

  • Salt and Pepper Corydoras

The salt and pepper corydoras are small-sized catfish species. Although these white and grey cories are fish that don’t need a filter, they require a water temperature of about 77-80 F. They live for about three years, depending on their care. Also, these cories species are bottom feeders that enjoy being in groups, so you should consider keeping them in 10-gallon tanks.

  • Pea Pufferfish

The pea puffer species are another small fish that don’t need a filter. They are originally from southwest India and are also known as pygmy pufferfish. These species used to be scarce but are now commonly traded in various pet shops. They grow to an average length of 1.4 inches and would require at least a five-gallon tank.

Unlike their marine variant, these species can survive without a filter installed in their tank. However, monitor the pH, so it remains between 7.0-and 7.8. Also, you would need a heater in the pufferfish tank as they thrive in temperatures between 73-84 F.

  • Platy Variatus

The platy variatus is a fish species that grows to an average length of 20 inches. It gets its name due to its elongated body and pointy oval scales. This species also have tiny sharp spines on each scale.

They are primarily herbivores but would occasionally prey on smaller species. These sleek, beautiful fish are hardy and active. Also, they would survive in a tank with the filter turned off for only a few days.

  • Scarlet Badis

The scarlet badis are beautiful fish that require at least a five-gallon tank to thrive. They are hardy, small-sized, and predatorial fish species.

You should keep them with other scarlet badis fish and ensure their tanks have enough hiding places and plants. It would help maintain peace in your home aquarium. Also, these species can also stay without a filter for a few days.

  • Ember Tetra

The ember tetra is small size hardy fish that require minimal care to survive. They are great for small tanks as they only grow to an average length of one inch. These species do not require filtration to be happy and can thrive without it for a few days. However, they require their pH to be around 6.6.

The ember tetra species are a close variant to the neon tetra and prefer to be in a group. They are adaptable but require a tank heater set between 73-84 F and love live plants in their tanks.

  • Sparkling Gourami

The sparkling gourami grows to an average size of 1.6inches. They require minimal care and are very attractive. These fish can survive without a filter for a few days, but you need to maintain a pH between 6.0 and 7.5. Also, they are peaceful and would need a minimum of 10 gallons to thrive.

  • Six-Ray Corydoras

The six-ray are small-sized fish that grow to an average size of one inch. They are bottom-dwelling fish that need at least 10 gallons of space and love a planted habitat. These species are originally from South America and require a tropical environment with temperatures between 72-77F. Like the other hardy fish species, the six-ray cories enjoy acidic pH levels between 6.0-and 7.2.

  • Pygmy Corydoras

The pygmy corydoras are small-sized and very easy to care for. They grow to the size of an inch and require warm temperatures between 72-79 F. They can withstand an acidic environment with a pH of 6.4 to 7.4, so they can survive without a filter for a few days.

They are bottom feeders and would mostly ignore other top-dwelling fish. Their coloration blend so well with the colors of substrate sand and gravel. In fact, a top-dwelling fish may not notice it has a tank mate!

Can a Fish Live Without a Filter?

Yes, a fish can live without a filter, depending on the tank setup. A filter is quite advantageous because it is a place that encourages beneficial bacteria growth. Also, it allows water flow and increases oxygen content in the tank. Nonetheless, your fish can survive without a filter if:

  • Your tank or fishbowl is well-established with sufficient sources of beneficial bacterial like the substrate
  • Your tank contains enough plants to increase oxygen levels
  • Your tank contains only a few fish,

In this case, the tank has other surfaces to grow beneficial bacteria. With the help of these good bacteria, the plants would then convert and eradicate toxins from the water column.

Furthermore, as the plants consume Co2, it would, in turn, give off oxygen which the fish requires to survive. However, if the oxygen content in your unfiltered tank is inadequate, you can add in an air pump. Other ways oxygen can get into the water column are by surface agitation and absorption.


1. Where To Keep a Fish That Doesn’t Need a Filter?

While considering keeping fish that don’t require a filter, you must first think about the best abode for it. The go-to option for the most fish keeper who does not want a filtration system would be a fishbowl. Yet, most of these bowls are too small for decoration or plants. Hence, the fish is likely to be raised in a Spartan-like habitat.

2. How Big Is a Fish Bowl?

The size of a fishbowl can get to be five to ten-gallon capacity depending on the brand. However, common fishbowls are usually between one to three gallons.

3. What Is the Best Fish Bowl Size?

The best fishbowl size depends on the size of fish you are keeping, its growth rate, and the location you plan to place it. Still, small bowls of about three to five gallons are considered best because they are aesthetically pleasing. Also, a bowl of about five gallons would comfortably accommodate most aquarium setup equipment like a heater and filter while leaving room for live plants and your pet fish.

4. What Kind of Fish Can Survive in a Bowl Without a Filter?

By default, the fish has to be naturally small-sized, adaptable, and a cold water species. The White Cloud Minnow fish species requires the least care in a bowl. They are a perfect fit because they do not require a tropical environment. Also, they are hardy enough to withstand poor water quality from time to time. Nonetheless, it’s the job of the fish keeper to ensure their pet fish is happy and comfortable even without a filter.

5. How Do You Keep a Fish Comfortable in a Bowl Without a Filter?

If you decide to keep your fish in a bowl without a filter, you should consider these minimal requirements to keep it happy.

– Heat

The common question most beginner fish keeper has is “Can Fish Survive Without A Heater?” The answer is yes, but it depends majorly on the fish species. If you plan to keep a tropical fish in a bowl, you need to consider a heat source of about 78F, or it may not survive.

To avoid trying to heat a fishbowl, here are some fish that don’t need heaters. Examples of cold-water fish species are barbs (gold, rosy, two spot, and green barbs), tetras( Buenos Aires and bloodfin), Danios(zebra and pearl), Guppies, White Cloud Mountain Minnow, and Weather Loach. They are all hardy and easy to find in pet shops.

– Water Changes

Every fish requires good water quality; however, the main concern is how you perform a water change in a bowl. A bowl with just one betta fish and lots of plants would not need water changes as often as a crowded habitat with little or no plants.

Hence, the setup would greatly determine the regularity of water changes. So monitor your water quality and create an ideal routine that would not strain the health of your fish. Then test the tank parameters and change the water as often as possible.

– Light

Lighting depends on the requirements of the fish and plants(if any). In some setups, you only need to keep your fishbowl in a corner of the room where natural sunlight can get to it. On the other hand, others may require standard aquarium lighting.

– Aquarium Plants

Most aquarium plants would grow well in a fishbowl. But you may want to stay away from tall-growing plants, or you may begin to struggle with partially immersed and submersed plants. Furthermore, plants requiring special lights may not be ideal for a bowl setup. This is because the tank would not have enough space to support a complete Co2 setup.

However, some live plants would do fine in a fishbowl. Some of these plants include java moss, java fern, Sagittaria, green hydrophilic, Vallisneria, Anubias hornwort, sunset hygro, Moneywort, rotala indica, Waterwheel Plant, and Rotala Rotundifolia.

6. Can a Fish Survive Without an Air Pump in an Unfiltered Tank?

Fish that don t need a filterYes, a fish can survive in an unfiltered tank without an air pump. The air pump aerates the tank, increasing oxygen in the water column. Nonetheless, a few factors may cause your tank to require an air pump. Here are a few:

  • If your plants do not produce enough oxygen naturally
  • Your filter is causing water surface disturbance which is slowing down the water’s oxygen absorption rate
  • Also, if your tank is an open or closed setup, it plays a crucial role in its oxygen content

7. What Fish Shouldn’t Be Kept Without a Filter?

Indeed some fish with minimal requirements would get away with leaving contentedly in a bowl without a filter, but others can’t survive it. For instance, aggressive fish that produce a lot of fecal waste should not be kept without a filter. Likewise, fish that would grow large is also not ideal for this kind of setup. Hence, here are some fish species you shouldn’t keep without a filter:

  • Angelfish
  • Goldfish
  • Barbs
  • Cichlids


For a fish to survive without a filter, it requires an ideal environment that includes an uncrowded, well-established tank with adequate numbers of live plants. Have you thought of raising a fish without a filtration system? Here are some facts to remember:

  • Not all fish can survive without a filter for long periods
  • Small-sized, cold-water, and hardy fish species are likely to survive without a filter in their tank
  • Even though a fish doesn’t need a filter to survive, create a water changing routine to provide good water quality for them
  • The White Cloud Minnow fish species are the easiest to care for in a bowl setup without a filter

Why not start you own unfiltered tank with a five-gallon betta or even guppy fishbowl set up?

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