Bettas are tropical fish native to Southeast Asia. They live in the warmer regions in their natural habitat, where the water temperature doesn’t drop much, even during winters. This is why bettas prefer to live in warm water in aquariums too. They can’t survive in a cold climate for too long.
Let’s now understand this in more detail.
Why Are Bettas Tropical Fish?
Bettas are tropical fish as they live in tropical areas in their natural habitat.
Bettas come from parts of Malaysia, Vietnam, Cambodia, and Thailand’s river basins of the Mekong and Chao Phraya rivers.
They primarily originate from tropical Southeast Asia, where the temperature is usually around 80°F year-round.
Bettas are found in the shallow waters of marshes, rice paddles, ponds, small streams, river basins, and drainage ditches.
These tropical regions don’t get very cold.
Even in winters, the temperature drops only up to 50°F. Most of the year, it’s pretty warm in these regions.
So bettas are more accustomed to warm climates.
The ideal water temperature for the optimum growth of tropical fish is in the range of 76°F to 80°F (25°C to 27°C).
In captivity, bettas need a temperature of 75°F to 82°F (23.8°C to 27.7°C).
This is one of the primary reasons bettas are considered tropical fish, as they need a warm climate to thrive.
What Are The Ideal Water Parameters For A Betta Tank?
Every fish species need specific water parameters to thrive.
Since bettas are sensitive to water conditions, it’s crucial that they get water parameters similar to their natural environment.
Bettas prefer soft, acidic water. Very hard water can be detrimental to their health.
So if the water at your place is hard, it needs to be treated with a water conditioner.
Conditioning the water also helps clean the impurities, thus making it safe for the fish.
The ideal water parameters for bettas are:
- Water Temperature: 75°F to 82°F (23.8°C to 27.7°C),
- pH level: 6.5 to 7.5,
- GH: 3 dGH to 4 dGH (50 ppm to 66.7 ppm),
- KH: 3 dKH to 5 dKH (53.6 ppm to 89.4 ppm),
- Ammonia and Nitrite: 0 ppm, and
- Nitrate: <20 ppm.
Alright! Now that you know bettas need warm waters, let’s also understand if they need a heater or they can survive without one.
Do Bettas Need A Heater?
Bettas need a heater. Being tropical fish, they thrive in warm water held at a stable temperature. Installing a heater in the tank is the most effective way to ensure stable water temperature.

Like most other fish, bettas are ectothermic. It means that their body temperature depends on the surrounding environment.
When bettas are kept in the optimal temperature range, their cells process food and waste efficiently.
It helps in their overall growth.
The only time bettas can thrive without a heater is when the room temperature remains stable.
But it’s highly impossible as the temperature drops at night, especially during the winter.
With no heater in the tank, the water temperature will warm up or cool down to room temperature.
Any sudden and drastic fluctuation in water temperature can be fatal for bettas.
Water that’s too warm or cool can become stressful to bettas.
Rapid fluctuations in the water temperature can also affect the metabolism of bettas.
Any temperature above 85°F is too hot for bettas.
High warm water can overheat the bettas and cause their metabolism to speed up. Bettas can become hyperactive in such instances.
On the contrary, if the water temperature drops below the desired level, it can slow down bettas’ metabolism.
This will make them sluggish and can result in loss of appetite, further weakening their immune system.
So it’s crucial to have a heater in the tank to maintain the water temperature for the optimal growth of bettas.
Can Bettas Live In Cold Water?
Bettas can’t live in cold water for too long.
They may survive for a few months, but prolonged exposure to cold water can be fatal.
Since bettas are tropical fish, they need heat to remain active and healthy.
If the water temperature drops considerably, it can affect them adversely.
Some of the issues that bettas can face if exposed to cold water are:
- Bettas will become lethargic because their metabolism will slow down to conserve energy.
- Colors will fade from their scales and skin. It will make them appear dull.
- Bettas can also lose their appetite if kept in cold water. As a result, they will lose their energy due to insufficient food intake. This can lead to starvation and deterioration of their health.
- Loss of appetite will further impact their immune system, making them susceptible to fungal or bacterial infections. They will become vulnerable to different types of diseases.
- One such disease that bettas can encounter is Popeye. This disease causes a fish’s eye to lump out of its head, and it happens if the water is inappropriate.
- Another fatal disease that bettas may fall prey to is fin rot. Fin rot is a common bacterial disease that makes the fins appear torn or ragged. Moreover, it’s highly contagious and can quickly spread to all the tankmates if left untreated.
- Low temperature also leads to slow functioning of the digestive system of bettas. It can result in bloating, constipation, and other health issues in bettas.
- Lastly, cold water holds less oxygen compared to warm water. So you might find your bettas gasping for oxygen at the water surface.