Betta Fish Care

Betta Fish Water Temperature

If you are a responsible pet owner and if you have ever had betta fish as pets, then you probably know how often it is challenging to imitate their natural habitat at home.

Betta fish are specific, tropical fish, with exotic color combinations and with a little bit of extreme behavior. Probably, that is why they are worldwide favorite fish pets. 

Undoubtedly, they attract attention and create joyful energy.  However, for betta fish to be satisfied and happy, the first and foremost is that the water temperature.  

For betta fish, the water temperature in the fish tank MUST BE 78-80º F (25.5-26.5º C). 

Although they can survive higher and lower, this does not mean that it is good for them. Like all fishes, bettas are highly sensitive. Almost every temperature change for just one day can harm them.

Bettas are lovely aquatic creatures, and if you treat them carefully can live up to 5 years. 

So, it is very important to know how to maintain optimal water temperature in a fish tank. 

Why Are Betta Fish so Sensitive to Water Temperature?

These colorful fish are native to Thailand and Southeast Asia, from areas of tropical and exotic climates. In their natural habitat, betta fish live in warm, calmer slow-flowing waters such as swamps, ponds, and ditches that naturally occur along roadsides. 

Betta Fish

Due to their tropical nature, bettas need warm water and aquatic plants for hiding but also spawning.

Most beta fish that can be bought in pet stores are specially bred for home aquariums. So, they are not the so-called wild bettas and have no experience of living in nature. Wild bettas are more adaptable and resilient, which has led to them evolving rapidly. 

The bettas we keep as pets are more sensitive. They are somewhat spoiled because of not having natural enemies. Bettas in aquariums live gracefully with no need to lurk in the dangers that are common to their natural environments. 

Fish are highly demanding pets, even though many do not think so. An ideal aquatic environment is not easy to create artificially in aquariums, but it’s necessary if we want our fishy friends to live long and happily. 

How to Ensure the Ideal Water Temperature?

Whether you have betta or some other fish species – it is important to provide them with a quality aquarium. Always keep in mind that you are creating an artificial aquatic environment and that, similar to nature, you have to adapt the conditions to the species of your pet fish. 

Fish tanks can be small or very large and due to their size, water and general accessories must be organized. Otherwise, the fish will not be happy and will probably die quickly.

Always keep in mind that betta fish are sensitive to both lower and higher temperatures than optimal.

So, for a start, a quality aquarium is basic. Then, water temperature and specific (non) mineral composition. 

The market is full of varieties of fish tanks, as well as the necessary accessories such as thermostats, heaters, and appropriate filters that regulate water quality. 

Whether you live in tropical or extremely cold parts of the planet – betta fish aquarium must have a suitable heater and an accurate thermostat. 

Make sure they work properly to warn owners if the temperature is above or below optimal. Remember, the water temperature must be ideal.

Whatever size is, place the fish tank in a quiet and shadowy place, where there is no direct sunlight.

Quality Heaters & Thermostats

There are indeed many types of aquarium heaters, and the most common ones are completely or partially submerged. 

  • Completely submerged heater – Since betta fish must always be at the ideal water temperature – our recommendation is a completely submersible heater. Whether the aquarium is large or small, this type of heater provides even heating and maintaining the water temperature. 
  • Partially submerged heater – It is also useful, but for a short time. Not very reliable and it takes time to warm water in larger tanks.

There are also pre-set and adjustable heaters.

  • Pre-set heater regulates and maintains the same temperature in the aquarium. Most of them are set at 78 degrees Fahrenheit and that’s it. They turn on and off automatically; you don’t have to pick and adjust anything. However, they are not very safe and reliable, but they are much cheaper.
  • The adaptable heater is probably a better choice. They are more complicated, but also safer. You will also need a special thermometer for this type of heater because before you adjust it, you first must know what the water temperature is. Adjustable heaters often come with a small light that signals that the heating process is in progress. When it switches to maintaining the mood, (when the water has reached the desired temperature) the light turns off. 

The general recommendation for betta fish is a heater with 5 Watts per one gallon of water. 

For large fish tanks, it is good to have multiple heaters.

There are different shapes and sizes of heaters depending on the size of the aquarium. Some are inconspicuous and can hide behind plants, rocks, and sand that you have in the aquarium. 

Round, rectangular, or torpedo style … whichever you choose, it is important to know what material they are made of and that they work properly. One of the innovations is heaters that you don’t keep in the aquarium, but under or on the side. 


No matter how expensive and quality a heater you buy, it will not have a thermometer. 

So, you have to buy it separately, because the heater is essentially worthless if you do not know what the temperature of the water in the aquarium is.

If your aquarium is smaller, you can also use a stick-on thermometer that changes color when the temperature rises or falls. 

Stick-on thermostats can be unreliable, so perhaps the best option is to buy removable ones. Dive into the aquarium and when it shows the water temperature – take it out. 

The thermometer must be precise and reliable, because only in this way will you avoid cooling or overheating the water, and eventually endangering the life of betta fish.

What Happens to Betta Fish if the Water is Not Adequate?

You will probably notice that your aquatic pet behaves differently than usual. 

If the water temperature is too low, the betta fish will behave similarly to a human being when it hibernates due to low temperatures.

It will adjust metabolic and physiological needs to the state of life support. Betta fish will be very calm, non-active, or will float on the surface. 

Over time, this behavior can lead to food rejection and the development of disease. In the long term, this state leads to death.

If the temperature is too high, betta fish will become too aggressive. He will behave scared and even hysterically. 

Similar to how a human being reacts to stress, this state of betta fish causes faster aging and, consequently, a shorter lifespan.

Don’t Panic: Just Gradually Adjust the Temperature

All fish are highly sensitive to temperature changes. 

Betta fish are no exception. Always keep in mind that these are tropical fish and that it is in such areas that they have evolved and survived to the present day.

If your betta fish have spent a few days at a lower or higher temperature, you will need to gradually get them used to the optimal temperature. They are already used to worse conditions and a sudden return to the ideal temperature can be stressful.

First, heat the water in the aquarium to the desired temperature, and then put the betta into a plastic bag that contains the water to which it is already accustomed. When the betta starts behaving normally, release it from the bag.

Yes, it sounds complicated and even tiring, but if you want your aqua friend to live long and happily, you have to be careful and patient with them.


Betta fish are a true gem of the aquatic world. Evolution has certainly benefited them and today bettas are one of the favorite and most widespread tropical fish that are popular as pets. To make sure that bettas adorn your apartment for as long as possible – provide them with water of ideal temperature.