Did you know that there is a whole class of fish that don’t require a heater and can survive at room temperature?
Unlike most pet fish, which require heaters in their aquariums to maintain tropical conditions, certain best cold water fish for aquariums such as cold water goldfish are perfectly content without one.
Therefore, if you are searching for what fish prefer low temperatures or fish that don’t require a heater, we’ve got it all! This article will introduce you to 10 fascinating types of cold water fish that can live happily in an unheated tank.
Choosing cold water fish for your first aquarium can be a smart decision since they are resilient and do not require constant monitoring of the temperature.
By opting for a cold water setup, you can also save space and simplify the maintenance routine for your aquarium.
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What Fish Prefer Low Temperatures?
1. Endler Livebearer
Meet the Endler’s Livebearer, a delightful small fish that is the best cold water fish for aquarium. These little guys bear a striking resemblance to miniature guppies and are constantly on the move, exploring every level of their tank.
Even though they aren’t typically found in coldwater habitats, they have shown to be highly adaptable fish that don’t require a heater.
Fun fact:
During the breeding season, Endler’s Livebearers put on a display of underwater ballet. As a mating ritual, the males show off their vibrant fins by flaring them in intricate patterns while gracefully swimming in zig-zags.
| Factors | Needed |
| Adult Size | 1–1.8 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 64–84 °F |
2. Paradise Fish
Q. What fish prefer low temperatures? Paradise fish is one of them!
The Paradise fish which is also known as the Chinese Fighting Fish, has captivating beauty but can be quite temperamental. It is recommended to keep the best cold water fish for aquarium with only their own species.
It’s one of those fish that don’t require a heater, bringing tropical fish elegance without much trouble. It’s best to house one male along with a few females, as they prefer inhabiting both the upper and middle regions of the tank.
Fun fact:
Male Paradise Fish construct nests made of bubbles on the surface of the water and protect their eggs and offspring once they have mated.
| Factors | Needed |
| Adult Size | 2.5-3 inches |
| Difficulty level | Easy |
| Tank Size | 20 gallons |
| Water Temperature | 72-82°F |
3. Panda Corydoras
The visually appealing “panda corydoras” have distinctive black and white designs, complete with a prominent black eye stripe. These stunning variations of catfish are ideally suited as the best cold water fish for aquarium, especially those that have been bred commercially to be less demanding.
Not only are panda corydoras pleasing to the eye, but they also have a reputation for being peaceful and sociable creatures. This makes them an excellent choice if you’re wondering, what fish prefer low temperatures and are peaceful at the same time!
Fun fact:
Panda Corydoras possess specialized barbels near their mouths that help them forage for food in the substrate.
| Factors | Needed |
| Adult Size | 1.2-2.6 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 72-82°F |
4. Zebra Danios
Additionally, these playful little swimmers tend to nip at the fins of long-finned fish, so it is advisable to avoid housing them together. To witness the social behavior of these fish that don’t require a heater, the best cold water fish for aquarium- Zebra Danios should be kept in groups where they will form strong bonds with each other – something unique in the underwater world.
Fun fact:
In their natural habitat, Zebra Danios are known to leap out of water when faced with threats or unfavorable conditions.
| Factors | Needed |
| Adult Size | 2 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 64–74 °F |
5. Leopard Danios
You don’t have to look for what fish prefer low temperatures anymore because Leopard Danios, much like their cousin Zebra Danios, can thrive in temperatures ranging from 64–80˚F. They have great adaptability to various environmental conditions and hence making them the best cold water fish for aquarium.
In terms of their requirements and social behavior, they closely resemble Zebra Danios as they exhibit high levels of activity and playfulness while generally maintaining peaceful interactions with tank mates.
Fun fact:
Leopard Danios are skilled jumpers capable of escaping from uncovered aquariums, making a secure lid essential to prevent escapes.
| Factors | Needed |
| Adult Size | 2.5 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 64–74 °F |
6. Two Spot Barb
Two spot barb is what fish prefer low temperatures- adding charm to your tank filled with fish that don’t require a heater!
One way to make the male Two Spot Barb look really vibrant and striking is by feeding it a balanced diet. You can do this by offering a mix of flake food, live food, and algae.
It’s interesting to note that even though it’s categorized as a Barb fish that doesn’t require a heater, it doesn’t actually have any barbels on its body. Instead, what catches your eye are the beautiful spots on its head and tail which go perfectly with its shiny silver body.
Fun fact:
The males of Two Spot Barb fish may display a vibrant red color temporarily during mating displays periods of excitement. They are amazing addition of the best cold water fish for aquarium.
| Factors | Needed |
| Adult Size | 2 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 64–78 °F |
7. White Cloud Mountain Minnows
White Cloud Mountain Minnows are not just the best cold water fish for aquarium due to their strength, but they also bring vibrancy to any aquarium with their gleaming scales.
They are ideal companions for goldfish, especially the smaller ones, as they require comparable water conditions and have a gentle temperament. These minnows flourish in temperatures ranging from 64-72˚F; however, it’s fascinating that Minnow fish that don’t require a heater can withstand even colder temperatures as low as 40˚F and survive outdoors during winter.
Fun fact:
Fun Fact: The White Cloud Mountain Minnows were once considered extinct but were later found in a secluded part of China during the 1930s.
| Factors | Needed |
| Adult Size | 1.2-1.6 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 64–72 °F |
8. Goldfish
Goldfish, often overlooked and underestimated, is actually what fish prefer low temperatures that thrive in both cold and temperate waters. They can even endure freezing temperatures by creating a small breathing hole in the ice.
With their wide variety to choose from, cold water goldfish are sociable and intelligent fish that make them a perfect choice for any cold water tank. It’s worth noting that cold water goldfish prefer water temperatures ranging between 60-74˚F.
Fun fact:
The cold water goldfish have an impressive memory capacity and are capable of recognizing their owners. They exhibit interaction behaviors when sensing their presence.
| Factors | Needed |
| Adult Size | 6-12 inches |
| Difficulty level | Easy |
| Tank Size | 20 gallons |
| Water Temperature | 64–74 °F |
9. Bloodfin Tetra
Observing the Bloodfin tetra is truly a delight due to its enchanting blend of colors, particularly when they are in groups. Similar to other tetras, these tiny fish are perfect for small tanks. Creating their habitat is effortless as they flourish in cold water and can tolerate a wide range of pH levels. Additionally, they adapt remarkably well to various decorations and arrangements.
Fun fact:
Observing Bloodfin Tetras is truly captivating, especially when they are seen in groups. Their red coloration becomes even more vivid, adding to their already stunning appearance.
| Factors | Needed |
| Adult Size | 1.5 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 64–82 °F |
10. Galaxy Rasbora
The stunning mix of colors on the galaxy rasbora (also referred to as CPD or Danio margaritatus) makes them the best cold water fish for aquarium, especially when they are kept together in groups. Like most tetras, these fish are small and can be comfortably accommodated in smaller tanks.
Creating an environment for rasbora fish that don’t require a heater is easy because they thrive in cold water, can tolerate different pH levels, and adapt well to various decorations and layouts.
Fun fact:
Galaxy Rasboras get their name from the mesmerizing iridescent spots on their bodies that resemble tiny swimming stars.
| Factors | Needed |
| Adult Size | 0.6-0.8 inches |
| Difficulty level | Easy |
| Tank Size | 10 gallons |
| Water Temperature | 72–82 °F |
Conclusion
To sum up, exploring the realm of the best cold water fish for aquarium provides an amazing experience for aquarium lovers to set up a captivating fish tank. From well-liked goldfish to more obscure yet equally enchanting species, maintaining a tank without heating can offer both beauty and space efficiency.
Regardless of whether you are new to this hobby or a seasoned enthusiast, the toughness and splendor of cold water goldfish or any other fish provide a delightful journey. Therefore, don’t hesitate to set up your own mini aquatic world that has fish that don’t require a heater.
Enjoy fishkeeping!
