Best Fish That Don’t Need a Filter (for a short time)

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fish that dont need a filter

If you’re thinking about getting a new fish tank and want to avoid the hassle of having to buy a filter, then this is the post for you. Plenty of great fish tend to do okay (not well) for short in aquariums without filters and can be housed in smaller tanks.

Every fish need a filter, and there is no doubt about that, so please always use a filter while keeping fish. 

A few species with daily water changes can do okay for a short time in a fishbowl without a filter or heater, and we will talk just about that.

Fish that don’t need a filter (for a short time) are those that can survive in low-water conditions, and some even thrive on it. What’s more, these fish usually have an appealing look about them, and they’re often hardy small fish that won’t require as much attention as other types of freshwater fish. 

There is a lot of fish out there that can be great additions to your aquarium. This blog will go over some of the different stocking options for bowls without filters.

Why Do Fish Need a Water Filter?

To make it clear once and for all: 

Fish need a water filter to survive and without it, they will die.
Please never keep your fish without a filter.

Fish can’t breathe air, so they use their gills to get oxygen from the water. If your tank doesn’t have any filtration system, your fish will be breathing in ammonia and nitrate,s which are toxic compounds that come directly from the fish’s waste!

These toxins can lead to respiratory problems. The good news is that many fish species can do okay for a short period in fish tanks or fishbowls without a filter.

Types of Fish That Don’t Need a Filter

The filter is critical and essential equipment for your fish to survive. A few types of them are more survival than others when it comes to water quality.

There are numerous fish species out there that don’t need a water filter (for a short time). We included three types of fish, and that’s for a reason:

Hardy Fish

The best fish that don’t need filters are hardy fish. Hardy fish are those types of fish that can live under tough conditions. They have high disease resistance, low maintenance requirements, and an incredible sense of temperature changes – meaning you never need to worry about your aquarium environment!

They can adapt easily and maintain a wide range of water parameters, making them the best fish for your fish tank that doesn’t have a filter.

Small Fish

Another thing to consider is the size of the fish. Small fish require less space and less water and reduce waste. By doing daily water changes, you can keep some specific types of them in your fishbowl, and there is no need for filters.

Cold-water Fish

The filter isn’t the only essential equipment to keep a fish. An aquarium heater plays a critical part in some fish species’ life. An aquarium heater is as big as a filter which means that we need to consider only those types of fish that do not need a heater and filter at the same time.

Cold-water fish can live in cold water at 68 degrees Fahrenheit. They are easy to care for and can survive under harsh conditions. That’s why you can keep them in an aquarium without a heater.

Best Fish That Don’t Need a Filter (for a short time)

Considering all the above, we made a list of the best fish that don’t need a filter for a short time. Before choosing your stocking for your tank, make sure the tank size is appropriate for that specific fish. All of the species mentioned below can do just well in a 5-gallon fish tank. 

Betta Fish

Betta fish are colorful and fascinating. They can survive for a short time in bowls or small tanks without a filter, but to thrive, they need the right environment- ideally around 77°F with plenty of covers! A heater is essential for Bettas.

fish that dont need a filter Betta Fish

It’s easy care as long you know how: just make sure there aren’t other aggressive Bettas in the same tank, or else they will fight. This interesting fish would look great sitting next to some plants on our desk at work.

Paradise Fish

Paradise fish are territorial and aggressive like bettas, but they prefer cooler temperatures. There is no need to purchase an aquarium heater for this type of fish. This type likes acidic environments where pH levels measure 5.8 on the scale: the high point being an 8 for very strong acidity.

fish that dont need a filter Paradise Fish

For that reason, Paradise fish is one of the fish that don’t need a filter and a heater. At least for a few days, they can survive if daily water changes are made. 

Zebra Danios

The Zebra Danios are colorful, social fish that grow fast. They need plenty of hiding places in order to feel safe and secure, so they can be happy. You’ll want to provide your Zebra Danios with at least three different shelters around the tank, one for each male/female pair.

fish that dont need a filter Zebra Danios

A Zebra Danio has an average lifespan of 2-3 years, depending on how well they are cared for by the owner. The optimum temperature is between 75°F – 82°F (24°C – 28°C), and Zebra Danio’s will eat mostly flakes

These fish can live a short time in tanks without a filter, especially if the tank is big enough. 

Ember Tetras 

Ember tetras are a lot of fun to have in your nano aquarium! They only require 5-10 gallons. These fish do well when they live in groups, so it’s best to keep at least six or more of them together.

fish that dont need a filter Ember Tetras

What you need for an Ember Tetra tank is a heater that can maintain a temperature between 72-77 degrees Fahrenheit. The water needs to be filtered by using either a sponge filter or an undergravel filter. But Ember Tetra is a type of fish that can do okay for a few days without one.

There should also be some rocks, driftwood, plants, and decoration around the tank! Lastly, make sure there are no sharp objects inside the tank because these fish have really sensitive fins that can get nicked easily!

Platy Variatus

Platy Variatus is a sleek and elegant fish that can grow up to be as long as 20 inches. It has an elongated body with pointed oval-shaped scales, which give it its name; they’re actually small sharp spines on top of each scale! 

fish that dont need a filter Platy Variatus

They’re beautiful, active, and very hardy. As long as you keep the water quality high, they’ll be happy. They don’t require a heater, and you can turn off the filter for a few days, and they will do okay. These fish are primarily herbivores, but they will also feed on smaller invertebrates when necessary.

Endler Guppies

Guppies are one of the easiest fish to keep in an aquarium. Because of their hardy nature, keeping guppies can be extremely rewarding. Their care is very basic, which makes them a great choice for both beginner and experienced aquarists alike. What’s even better is that you can breed your own Endler Guppies at any 10 gallon fish tank or bigger, so they are really quite sustainable.

best fish for 5 gallon tank Endlers Livebearers

Endler Guppies are one of the best fish to keep in your community tank. They are extremely active and tend to be peaceful towards other tank mates. However, It is important to remember that they will do better when kept in small groups (3-5).

Begin small in size Endler Guppies can be considered as a fish that doesn’t need a filter for a short period of time. Assuming that you keep it inside a big tank and do water changes frequently. 

White Cloud Minnow

White Cloud Minnow requires clean, well-oxygenated water with a pH of 6.5-7.0  (6.8 is ideal).  Their behavior is slightly different depending on the pH.  Below 6.8, they are more aggressive and may nip at each other’s fins.  Between 6.8-7.0,  fin nipping or any fighting is less likely to occur above 7; the fish are again more active around one another.

fish that dont need a filter White Cloud Minnow

You can feed them live or frozen brine shrimp and daphnia.  They also eat worms and bloodworms, as well as fresh vegetables such as zucchini, cucumber, and peas. This species likes warm water above 80 F (26 C) but does not go over 86 F (30C).

Keeping them in a fish tank without a filter it’s possible. White Cloud Minnow are hardy fish that can sustain swings in water quality. Even tho this fish is one of the best fish that don’t need a filter, don’t let it too long without one; otherwise, it will have consequences. Clean water is essential for every fish, so regular water changes and a filter need to be provided in the future. 


One thing is for sure, there is no fish that don’t need a filter. Some fish species tend to do okay, even in dirty waters for a few days or be. Even for this hardy fish, daily water changes need to be done, especially if you don’t use a filter.  When searching for fish that don’t need a filter, you need to choose the one that doesn’t need a heater. Coldwater fish is the best one in this case.

A fish species that accomplishes all of these is Paradise fish. Keeping them in a fish tank doesn’t require a heater as they like cold temperatures. As hardy fish, they tolerate changes in water parameters. They are also small, meaning that they don’t produce too much waste. Keeping them in a fish tank without a filter is possible but not a lifetime solution.

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I am Mario, a experienced fish keepr and the editor-in-chief of Epic Aquarium.

At Epic Aquarium, we take our commitment to providing comprehensive and unbiased reviews very seriously. Our team carefully reviews each product, and we only recommend the very best in terms of quality. We also consult with leading fish keeper experts to ensure that each article is based on the most reliable and up-to-date information available.

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