Many new fish keepers want to begin their journey with a smaller fish tank and maybe one or two fish. With this thinking, many people select a 1 gallon tank then wonder, “Which fish is the best fish for 1 gallon tank?” Since the size of the 1 gallon tank is small, your selection of fish is indeed less. The good news is that smaller fish are not fussy and generally easier to care for—as long as you do research.
Which is what brings you here right? If you are looking for suggestions about the best fish for a 1 gallon tank, you have come to the right place.
Let’s learn more about 1 gallon tanks and what kind of fish are best for these small worlds.
Considerations About 1 Gallon Fish Tanks
Before we get into the list of the best fish for 1 gallon tanks, we need to discuss briefly about the importance of maintenance and why keeping fish in a bowl or tank without a filter is different from keeping them in a larger tank. This is generally the typical setting of a 1 gallon tank (sometimes called a nano tank), since they are so small to begin with.
A common problem with 1 gallon tanks is that they are underestimated. Beginners think that a smaller tank will be less of a challenge, but that is never the case. The reason many experienced people choose not to use a 1 gallon fish tank (or bowl) is this: it can be difficult to keep clean and aerated and moderated.
The temperature will fluctuate wildly if you do not use a heater or have a decent source of light, and that can negatively impact some fish. Since heaters are rated for 2.5 gallons and above, you will need to consider having fish that can manage cooler water temperatures. Ammonia and nitrates spike easily in lower volumes of water, and that is one important aspect to consider if you want to keep a 1 gallon tank.
Cleaning is a must for 1 gallon tanks or bowls, especially those without a filter. Dirty water means sick fish. Change the water frequently and avoid using tap water often, since chemicals may be present that harm your fish.
Another concern from experienced fish keeps is that, aside from unstable water parameters, there is very little room for fish to swim in a 1 gallon tank. Thinking about the lack of swimming space, people also ask this question: “How do I know my fish will be happy in a 1 gallon tank?”
Well, there is no way to openly communicate with a fish, so you need to read up on their behaviors and learn to recognize different resh signs. If you watch your fish regularly and take good care of them, then you will also know when they aren’t doing well. Sometimes, a 1 gallon tank will be too small, even for fish that usually don’t mind a smaller space.
The Best Fish For 1 Gallon Tank or Bowl
Sure, you might have a small fish tank, but that doesn’t mean it can’t be a vibrant habitat or keep a boring fish in it. Here are some suggestions for the best fish for 1 gallon tank:
1. Betta Fish
The first option many people consider is the betta fish, also known as the Siamese fighting fish. Betta fish can be aggressive, so they do well alone, living in their own little world.
As long as you add a live plant for oxygen and some decent substrate, your betta fish will be happy. Plus, betta fish are remarkably resilient. Simply check the water of the 1 gallon tank frequently and conduct routine water changes.
In proper conditions, betta fish can live 3-5 years. You can even train these intelligent and curious fish to do tricks.
Ghost shrimp, cherry shrimp, amano shrimp, and blue velvet shrimp might not be fish, but they do take to nano tanks extremely well. Same as the betta fish, you will need to use a slim heater for the 1 gallon tank, since they are susceptible to temperature fluctuations.
You must maintain a temperature of around 70-75 degrees F (21-24 degrees C). Otherwise, shrimp of any kind do not produce a high bioload and are not as vulnerable to shifts in ammonia and nitrates like other fish. If you want a hearty inhabitant, shrimp may be a good option for you.
The only thing you need to be careful about is the plants that you may use to aerate the 1 gallon tank. Shrimp of any kind of omnivores and may decide to eat the vegetation instead of the pellet mix you give them, especially if the fish food is not that good of quality.
Another favorite fish for 1 gallon tanks is the guppy. These fish come in hundreds of color combinations, are reasonably priced in the pet store, and are a joy to watch swimming around.
Guppies grow to around 1.25 inches in length, so you can get a couple of them for a 1 gallon tank. Keep in mind that males are smaller than females—3-4 males will fit as opposed to 2-3 females in a 1 gallon tank or bowl.
In general, guppies live for about 2 years, but you may be able to keep them slightly longer if they are well taken care of.
Guppies are also a gregarious fish and don’t mind being housed with other fish types, but they also tend to like live plants in their tanks. Therefore, it is best to get guppies only if you have vegetation available. You may also need a small filter for the 1 gallon tank.
4. White Cloud Mountain Minnows
The white cloud mountain minnow is another that is considered one of the best fish for a 1 gallon tank. Similar to neon tetras in appearance with temperaments like guppies, these brightly colored minnows will school together.
Make sure you have enough room for 2-3 of them, at least. Since white cloud mountain minnows can grow to about an inch in length, the maximum amount for a 1 gallon tank is 4 fish.
Secondly, they are hardy, making them ideal for beginners and younger tank owners. As long as you maintain constant parameters for temperature and cleanliness, you will have them for a couple of years.
These minnows are also not very picky, energetic, and fun to watch. Add a couple of live plants, and they will be happy and entertaining.
One of the best fish for 1 gallon tank would have to be the tetra. Available in a broad range of colors, such as neon, glo, green neon, and ember, these tiny fish are perfect for bowls.
Although loud in appearance, tetras are peaceful and happy when in the presence of other fish. Since they school, you will have to have at least 2-3 tetras in the bowl, which also means you cannot let live plants get too big.
Give your tetras a mixed diet of freeze dried foods and pellets, and maintain a temperature of 75-84 degrees F. Also, they can tolerate water with a pH between 5-7.8.
6. Pea Puffer fish
Also known as the pygmy pufferfish, the pea pufferfish is a super small species that is indigenous to Southwest India. Recently, aquariums and pet stores have started including these little guys. Because of their small size, these pufferfish do swimmingly in nano tanks smaller than 5 gallons (yes, even a 1 gallon tank).
Interestingly, pea pufferfish are not like marine pufferfish. While their cousins need salt water, the pygmy type lives only in freshwater. Their ideal conditions are around a pH of 7-7.8 and a temperature of 73-84 degrees F.
This kind of environment may be hard to maintain, however; so make sure you’re up to the challenge. They are also carnivorous, usually eating small snails. Give them meatier food options.
7. Pygmy Corydoras
While other kinds of cories are usually not fit for tanks smaller than 5 or 10 gallons, the pygmy corydoras is tiny enough to do well in a 1 gallon tank. They are also very friendly and can be seen swimming around with other fish that may be present, such as ember tetras or danio. They also like shrimp and fry and snails.
Mid-dwellers, pygmy corydoras are usually seen hiding around plants, their silver and black-streaked bodies standing out among the green. Very easy to care for, you can give them any kind of sinking food. Their ideal tank parameters are 72-79 degrees F and a pH range of 6.5-7.0.
8. Zebra Danios
The energetic and inquisitive zebra danio, also known as danio rerio, is a great fish for nano tanks and bowls. They are tiny fish that grow up to 2 inches long.
As you can probably guess, zebra danio have a zebra-like pattern on their bodies—a combination of silver and black stripes. The preferred temperature range for these fish is between 64-74 degrees Fahrenheit. Ideal pH is around 6.5-7.
Zebra danios are hearty and will live 2-3 years with excellent care in small bowls, making them one of the best fish for 1 gallon tank. The only downside to zebra danios is their tendency to nip at brightly colored tank mates. If you plan on getting danios, you may want to avoid mixing them with glofish and similar varieties.
Where Is The Goldfish?
Believe it or not, the popular standby, the goldfish, once often seen in many fish bowls around the world, is not considered one of the best fish for 1 gallon tank for a couple of reasons.
First, that tiny fish you get at the carnival or in the pet store is going to grow. Rapidly. There are over 20 breeds of goldfish, and all of them have a minimum of 6 inches (15.24 cm) in length. That means you need at least a 10 or 20 gallon tank for a single goldfish to be happy. Other fancier breeds can grow up to 12 inches (30 cm)!
So don’t get tempted. Save the goldfish for much larger tanks and stick to nano and pygmy fish species for the time being.
1 gallon tanks might be small in size, but that doesn’t mean they can’t be beautiful and cozy for the fish inside. Most beginner aquarists will choose nano tanks or even 1 gallon fish bowls because the size is less intimidating than larger aquariums, but since these tanks are a bit harder to maintain, you will need a hardier fish.
With that said, there are quite a few fish that can survive happily in tiny tanks, such as goldfish, betta fish, and shimmering tetras. Now that you know what kind of fish are available for 1 gallon tanks, you will be able to find the one (or two) that’s right for you!