There are some but not many fish species that can live in an aquarium or a fish tank without needing a filter. Basically, any hardy fish can survive in a filter-less tank.
But what is a hardy fish? A hardy fish is any fish that is extremely easy to care for because it can adapt to a wide range of water parameters e.g. pH, kH, temperature and so on.
Hardy fishes are usually considered good starter fish. This is because beginners without much experience can easily maintain them without doing them much harm even when they are a bit careless.
Hardy fish are also perfect for people who are always busy and do not have much time to maintain fish tanks. In this article, I will share with you examples of hardy fish or fish that do not need filters.
But before I do that, there are a few important things you need to know about fish that do not need filters.
Before we get into all of this, get a filter for your tank. There’s no excuse for not doing it.
What you need to know before keeping fish in a tank without a filtration system
- Even fish that do not need filters actually need filters.
Yes, I know I am going to share with you examples of hardy fish that do not need filters to survive. However, I feel that it is important for me to let you know that every aquarium or fish tank needs a filter. This is because a filter will not only clean your tank of toxic waste but also oxygenate the water. So if you need the fish you are keeping not just to survive but thrive, you need to acquire a filter ASAP.
- Filters are not that expensive and are available in many types
If you are considering hardy fish because you think fish tank filters are expensive, you are wrong. Some filters go for as low as ten bucks. So do not go for hardy fish or build a filter-less aquarium just because you think filters are expensive. There are many cheap and quality filters available on Amazon and other marketplaces. There are also many different types available including small ones for nano aquariums.
- You can keep a fish in a tank without a filter if you do water changes regularly
If you are not going to get a filter for your fish tank, then you are going to need to do massive water changes perhaps after every two days. This is because the fish you are keeping will regularly release ammonia as waste. And the accumulation of ammonia in the tank will quickly become toxic for it. Normally, a filter will get rid of the ammonia and other waste in the tank. But since you don’t have one or intend to have one, you will need to change the water regularly to ensure your fish stays in a fresh, ammonia-free, and healthy environment.
- You can also keep a fish in a tank without a filter if you add live plants
I have already pointed out that all fish need to live in a tank with a filter system. A tank without a filter will not enable your fish to thrive even if it is a hardy fish. Nevertheless, one way you can keep a fish without a filter is by changing the water regularly. The second way is by having live plants in the water. This is because the plants will absorb the toxic ammonia waste released by the fish and, therefore, clean the tank naturally. However, if you intend to use this method to maintain the healthiness of your fish tank, you will need to keep only one or two fish in your tank because keeping more will mean they will release more ammonia waste than your live plants can handle. You will also need to buy an air pump to keep the water circulated and oxygenated.
As it is evident from the important information above, fish can only thrive in a tank with a filtration system. In a tank without a filtration system, fish can only survive. Moreover, only a few types of fish can survive for long in a tank without a filtration system. They are known as hardy fish. But as pointed out above in points 3 and 4, it is plenty of hard work to ensure the environment your hardy fish is staying in remains safe and healthy for it.
Now that you know what you need to know before keeping fish in a tank without a filtration system, it is time for the big reveal. Here are some of the few types of fish that don’t need filters.
Fish that do not need filters
It is kind of common knowledge to many people that bettas do not need a filter. If you Google “types of fish that do not need filters” one of the most prominent answers will be bettas.
Betta fish are available in vibrant and exciting colors. They are also known to be very fun and playful. Kids love them and even visitors to your house will be impressed by them.
Moreover, if you decide to keep a Betta, you will love it because they are low maintenance fish. They do not need a lot of care and do not really need a filter. So you can keep them in a bowl or a small filter-less tank. However, even if they do not need a lot of care, you need to maintain the healthiness of your bowl or tank by changing the water frequently or by having live plants.
A betta fish can live up to five years if you tank good care of it.
- Betta fish are a breeze to maintain
- They are beautiful and attractive
- They can be trained to do tricks
- They are fun for children
- They are not messy (do not release a lot of waste)
- They are territorial and fight other fish
As you can see above, there are many reasons to keep a Betta fish in your fish tank. They are the most popular fish to keep in a filter-less tank or a fishbowl.
Guppies are kind of like Betta fish in the sense that they are also very colorful and attractive. They are also similar to Betta fish in the sense that they do not release a lot of toxic waste and can, therefore, live in a filter-less tank.
Guppies are available in many colors including blue, green, yellow, and red. If you get one or two, you can make your fishbowl or filter-less tank very mesmerizing to look at.
Guppies are docile so they can live with other tank mates.
The best thing about them is that they do not need a lot of care.
- They are available in many colors
- They are a breeze to maintain
- They are cheap
- They have a relatively short lifespan of 2 years
Goldfish are a very popular type of bowl fish. If you have ever seen a goldfish, it was most probably in a fishbowl. This should tell you that they can survive without a filter.
The best thing about goldfish is that they are great starter fish. They are perfect for beginning aquarists because they are fun and they are hardy fish. However, there is one thing that you will probably not like about them – they are very messy.
So if you want to keep one or two, you will need to do water changes frequently and to have many plants in your bowl or filter-less tank.
- Goldfish have a long lifespan (can live up to 10 years)
- They are fun to look at
- They are a breeze to maintain (at least at first)
- They become messy as they grow
- They are a bit expensive
A zebra danio is perhaps the cheapest hardy fish you can keep without a filter. This is because it is dirt cheap. However, this does not mean that it is any less attractive. In fact, zebra danios are quite attractive and pleasing to look at.
This hardy fish is perfect for a filter-less aquarium or a fishbowl because it produces very little waste. It is the exact opposite of messy.
- Zebra danios are very cheap hardy fish
- They are easy to maintain
- They are small and can live with bowl or tank-mates
- They often live for about two years
In my humble opinion, Endler’s Livebearers are the most attractive small fish. They are very beautiful and calming to look at.
Endler’s livebearers look just like guppies and can easily be confused. But they are the better bowl fish or filter-less tank in my opinion.
- Endler’s livebearers are easy to maintain
- They are available in exciting color patterns
- They are affordable
- They require very good care to have a long lifespan
All fish need to live in a tank with a good filtration system to thrive. However, some can survive for long in a tank without a filtration system and they are known as hardy fish. The best hardy fish include bettas, guppies, and zebra danios. The reasons why include the fact that they release very little waste and are easy to maintain.