Our earth is a beautifully diverse planet, capable of supporting life at an incredible range of temperatures. The water alone ranges from colder than freezing to 750 degrees Fahrenheit, and there are living organisms that survive and thrive at these temperatures. Of course, “warm” and “cold” are subjective measures that range from species to species, but what do those words mean to betta fish? What temperatures do they prefer, what temperatures can they live in, and what temperatures do they thrive in?
Betta fish have an ideal temperature range between 78-82 degrees Fahrenheit, though they can survive a wider range. However, they will get sick much easier if they are kept at an improper temperature, though it is also possible to extend their lives by keeping them at the wrong temperature. It is a delicate balance that often ends in disaster, so it is best to simply keep them at the recommended temperature.
In this article, we will discuss the proper temperature for betta fish, different types of fish based on temperature preferences, whether or not bettas can live at room temperature, how to tell if your betta is cold, how long bettas can live in the cold, and how to properly heat a betta’s tank.
What is the Right Temperature for a Betta Fish and Why?
Betta fish do best between 78-82 degrees Fahrenheit, though they can technically survive a range between 65-90. However, this often causes serious negative health effects. A temperature of 78-82 degrees is recommended for bettas because their metabolism and immune systems function best at this temperature.
Fish are cold blooded animals, which means they rely on the external environment to produce heat for them. They are not capable of generating their own body heat as humans can. When the water gets too cold, their body functions slow down to the point that they can become impaired. In particular, bettas kept between 65-76 degrees have more digestive issues than those that don’t and are more prone to developing bacterial and fungal infections.
Their digestive systems cannot digest food as quickly at lower temperatures, which often leads to constipation and bloat. These conditions can devolve into much more serious, and even life-threatening ones. If your betta is being kept in colder water, you need to monitor them very closely for any signs of bloat.
In addition to side effects with their digestive systems, a betta’s immune system is less effective at lower temperatures. There are always pathogens in aquarium water, but they are normally not an issue, as any healthy fish is fully capable of fighting them off. However, as soon as a fish’s immune system is impaired, they are open to all sorts of diseases.
Are Bettas Tropical, Temperate, or Cold-Water fish?
Tropical fish need warm water to survive, and are not capable of living in water less than 60 degrees. Temperate fish can survive the widest range of temperatures, normally anywhere from 40-85 degrees. Goldfish, and most other large pond fish, are a good example of this type of fish. Cold water fish are the opposite of tropical fish; they survive and thrive in cold water and are not capable of living in warm water. For them, “warm water” ranges depending on the species, but is generally anything above 45, 55, or 60 degrees Fahrenheit.
Since bettas cannot survive water under 60 degrees and prefer water in the high 70’s, they are tropical fish. Their natural habitat is warm year-round and dominated by a wet season and dry season rather than 4 distinct seasons.
Can Bettas Live at Room Temperature?
There has been an ongoing debate for decades as to whether or not bettas can live at room temperature. The answer is yes, they can live at room temperature, but they often cannot thrive at room temperatures. In some areas, particularly in Thailand and similar regions, heaters for bettas are unheard of, as the typical water temperature is between 80 and 90 degrees. In these areas, heaters are wholly unnecessary, but if your room temperature is around 65-75, a heater is very useful.
As previously mentioned, bettas can live in these temperatures, but they are much more prone to developing an illness, bloat, constipation, or an even worse condition. It is fully possible to keep them at a lower temperature, but why do so when it actively harms them?
Cold bettas are lethargic bettas, and this can even lead to them developing depression (bettas are surprisingly advanced enough to develop depression, and can even be treated with antidepressant medications), which, as you may imagine, isn’t a lot of fun for your fish. Bettas are intelligent creatures, fully capable of feeling pain, cold, and other unpleasant sensations. Keeping them in constant cold water is bad for their health and overall well-being. Some will survive, and due to the lowered metabolism, they may even live longer than their normal lifespans. However, the quality of their lives will be much lesser.
How Can You Tell if Your Betta is Cold?
Aside from an aquarium thermometer, you will probably be able to tell if the water is too cold based off of the appearance and behavior of your betta. They often act sick when the water is cold, so it is important to keep an eye on them for a few days to ensure they’re not actually sick.
When kept in cold water for an extended period of time, a betta’s coloration will dull and gray. They will become significantly more lethargic, be more prone to bloat, and will become more bloated or fatter by eating the same amount of food. As the water gets colder, their metabolism slows down, meaning they do not need to eat as much food as normal. If you continue to feed them the same amount of food, they will be at risk of becoming obese.
How Long can Bettas Live in the Cold?
In all technicality, bettas can surpass their normal lifespan if you keep them in cold water. Their normal water temperature keeps their metabolism high, which keeps them healthy, but also reduces their lifespans. With a slower metabolism, bettas can live for a longer period of time, but only if you can manage to keep them healthy.
However, if you attempt to keep a betta in water under 60 degrees for an extended period of time, they will pass away very quickly. One way to humanely euthanize a betta is to quickly lower the water temperature, normally with ice. After a while, their body will completely stop functioning, and they essentially will fall asleep. While this process requires very cold water, a similar process happens to all bettas kept in water under 60 degrees. Eventually, their bodies will be unable to function, and they will die. If the water is in the 40’s, this will happen within a few minutes to a few hours. However, if the water is between 65-70, your betta can live several years, though the increased risk of disease makes this unlikely.
In conclusion, betta fish do best in water between 78-82 degrees, but there is a slightly wider range that they can live in. It is possible to keep bettas in colder water, down to 65 degrees, but their immune systems and digestive systems will not be able to function properly, which leads to the deaths of many bettas.