Betta Temperature Shock Symptoms And Treatment

Last Updated on 2023-11-16

Knowing what betta temperature shock symptoms are and how to treat them is extremely important. It won’t take long for a betta to succumb to temperature shock, so if you think it’s happening, you’re going to have to act quickly. Luckily, after reading this article you’re going to know everything you need to know about temperature shock.

Key Takeaways:

  • Betta fish are susceptible to temperature shock, which can occur when the water temperature in their tank becomes too low or too high.
  • Understanding the symptoms of temperature shock is crucial for the well-being of bettas.
  • Symptoms of cold temperature shock include lethargy, resting at the bottom of the tank, slipping into a coma at extremely low temperatures, and increased susceptibility to illness.
  • Symptoms of hot temperature shock include rapid breathing, staying at the surface, erratic swimming, and increased stress due to excess energy.
  • Common causes of rapid temperature changes include changes in room temperature, adding a betta to its tank, and water changes.

If you’re not in the mood to read, check out the video!

What Is Temperature Shock?

Before you find out what the symptoms are and how to treat it, it’s important to know what temperature shock is. In most cases, it’s when the temperature in your tank becomes too low. However, it’s also possible for a betta to get temperature shock from temperatures that become too high.

Betta Temperature Shock Symptoms

Sometimes knowing what to look for is going to be the key to saving your betta. So being aware of common betta temperature shock systems is vital for the wellbeing of your fish.

The symptoms of temperature shock are going to vary depending on whether the water has become too hot or too cold. Here are some of the most common symptoms.

Symptoms Of Cold Temperature Shock

If the temperature in your tank falls below the recommended safe level for bettas then you may notice some or all of the following symptoms.


The most common sign of temperature shock is lethargy. Fish are cold-blooded, so unlike mammals who generate their own heat, they can only absorb warmth from the water.

When the water is too cold to do this, they’ll often stop moving. The cold will make swimming and moving in general difficult for them, so they’ll avoid it as much as they can.

Resting At The Bottom Of The Tank

Another common sign is that your betta will rest at the bottom of the tank. This may be because it’s too hard for them to swim to the surface, or simply because they don’t have enough energy.

Slipping Into A Coma

At extremely low temperatures your betta may even slip into a coma. At this point, you’d have to act extremely fast to save them.

This happens because your betta’s body functions become so slow, he’s no longer getting enough oxygen to his brain to function.

It’s important that you don’t mistake being in a coma for being dead. If you think your fish has succumbed to rapid cold temperature shock then you should try to warm the water up as quick as possible. If after, a few minutes he starts moving again then you’ve just saved his life.

Becoming Sick More Often

A healthy betta should rarely become sick. So if you notice there’s a direct correlation to your bettas immune system and the temperature of the tank it may be time to warm it up a little.

Symptoms Of Hot Temperature Shock

As well as cold temperature shock (while it’s less likely) your betta can also suffer from hot temperature shock. Fortunately, hot temperature shock isn’t as severe. However, that doesn’t mean you should do nothing.

If you notice the temperature is too hot, you should do what you can to lower it back to a good level. Here are some of the common symptoms of hot temperature shock.

Breathing Rapidly

One of the first things you may notice is your betta breathing rapidly at the surface of the tank. While it’s normal for your betta to breathe from the surface it should appear natural.

When water becomes warm it can’t hold as much oxygen as colder water. So if you notice this, the temperature in your tank is too warm.

Staying At The Surface

As well as breathing rapidly your betta will also try to stick to the surface. A small pocket of highly oxygenated water normally falls just below the water line in fish tanks.

If your betta is struggling to breathe then you’ll notice him trying to stay near the surface and amongst the oxygen.

Erratic Swimming

You will notice your betta also swimming erratically and quickly. When the water in your bettas tank heats up too much, your betta will have too much energy.

This sounds like a good thing but in reality, it’s not. This level of energy is only going to stress your betta out. There are a number of reasons stress is bad for bettas, but the biggest one is that it’s going to weaken his immune system.

(If you want to know more about the ideal temperature for bettas, then check out this article!)

Blue Betta

What Are The Most Common Causes Of Rapid Temperature Change?

If you know the most common causes of rapid temperature change, then you can more easily prevent it. Here are some of the most common times your betta may suffer from temperature shock.

A Change In Room Temperature

In the summer or winter, you may notice the temperature in your room changing dramatically. If the sun shines directly into your room, or if your house becomes particularly cold in the winter then your tanks temperature can swing dramatically as well.

This is more likely to happen in tanks that are smaller. The bigger a tank is the less susceptible it’s going to be to temperature change.

When You Add Your Betta To His Tank

Another time that temperature shock is extremely common in bettas and all fish is when you’re adding them to their tank. That’s why it’s so important that you give your betta time to adjust instead of pouring him into his new tank straight away.

During Water Changes

And lastly, it’s also common for temperatures to change dramatically during water changes. If you add cold water into your tank straight away it’s going to reduce the temperature of the tank rapidly.

As you’re about to find out, there are actions you can take to avoid all of these things happening!

(Find out more about the perfect betta water temperature.)

betta care facebook group

What Can You Do To Prevent Betta Temperature Shock?

Thankfully there are a few things you can do to help avoid temperature shock occurring in your betta.

How To Avoid Cold Betta Temperature Shock

If you’re interested in learning all the ways you can heat up a tank then you should check out this article, which gives you information on what to do when your heater breaks

However, the main things you can do are:

  • Turn the heating up in your tank.
  • Move your tank away from windows and into warmer areas of the house.
  • Add hot water to a bag and float it in your tank.
  • Close the lid on your tank to keep the heat in.
  • Wrap your tank in towels or anything that will keep warmth in, or an electric blanket.
  • Move heat emitting items such as lamps closer to your tank.
  • If you’re performing a water change, then allow the water to warm up a little bit before you add it to the tank.
  • And in extreme cases, you can even set up tea lights around your tank.

How To Cool Down A Fish Tank

While hot Betta temperature shock isn’t going to be as severe as it’s counterpart, it’s still best to be avoided. And while it’s more difficult to reduce the temperature, it’s not impossible. Here’s how to cool down a fish tank!

Let A Fan Blow Across The Surface

One of the best things you can do is let a fan blow across the surface of the tank. Using a fan is going to do two things.

First of all, you’re going to blow cold air into the tank which will cool it down. And secondly, the air is going to evaporate the water in your tank quicker which will also help cool it down.

Fortunately, aquarium fans are extremely inexpensive and extremely easy to set up. In fact, you can get them off Amazon for $20-$30Temperature Shock.

Turn Off Your Heater

If you’re going to be in the vicinity the whole time then why not turn your heater off for a little bit. This is also going to be the ideal time for you to check everything is in order.

A temperature rise in your tank could be due to a faulty heater, which means you may need to purchase another one. Just make sure you don’t leave the heater off for too long or it might struggle to warm the water up once it’s back on.

Perform A Water Change

As you’re well aware a water change can often change the temperature in your tank causing it to drop to dangerous levels. However, this doesn’t have to be a bad thing.

If your water is getting too hot, then try performing a partial water change of 5-10%. You don’t want to drop the temperature too rapidly. But just enough to cool the temperature to safer levels.

Add An Aquarium Chiller Heater

Depending on your budget and the size of your tank you might also consider investing in an aquarium chiller heater. Aquarium chiller heaters siphon water out of the tank where it can be heated or cooled to the perfect temperature before being added again.

There are a lot of different chiller heaters on the market, but as you can see, not all of them are expensive!

Turn Off The Lights

The majority of energy in lights isn’t spent on keeping the light on. In fact, most of it gets wasted in excess heat. If the temperature of your tank is too high then leave your tank lights off.

Add Frozen Ice

If you have a bottle or container that can fit in your tank it may be worth adding frozen ice. Just freeze some water in a bottle and make sure you clean the outside thoroughly so there are no chemicals on it.

Once the water is frozen, place it in your tank until the temperature drops to the level you want and then remove it again. Repeat this as necessary.

Make Sure You’re Aerating The Water

And lastly, while it won’t necessarily cool down the water a lot you should make sure you’re aerating the water. Warm water doesn’t contain as much oxygen as cold water, so if your tank is getting too hot, you need to make sure you’re supplying it with enough oxygen.

Now that you know how to cool down a fish tank you also need to know what temperatures are dangerous for bettas.

Betta Splenden

What Are The Max And Minimum Safe Temperatures For Bettas?

Ideal Temperature Range for Bettas
Ideal: 78-80°F
Tolerable: 76-85°F
Critical: Below 74°F and above 86°F
Temperature Shock Fatality
Fatal if below 76°F or above 85°F over time

Bettas have a very strict need when it comes to the ideal temperature. Their ideal temperature is between 78-80°F. However, they can survive in temperatures as warm as 85°F and as cold as 76°F.

Below 74°F is when you’ll begin to notice the effects of temperature shock affecting your betta rapidly, and above 86°F he’ll begin slowly roasting to death in the water.

Is Temperature Shock Fatal?

If the temperature exceeds or falls below 85°F or 76°F then it will become fatal over time.

The more likely scenario when temperature shock will be fatal is during a rapid change in temperature. For example, if you just place your betta into an environment where the temperature changes from 78-85°F straight away, then his body won’t have time to adjust.

So the best way you can stop temperature shock being fatal is by making sure that you never let the temperature change too rapidly.

In Conclusion

In conclusion, temperature shock is going to be extremely dangerous for your betta. That’s why it’s so important to know the betta temperature shock symptoms as well as checking the water regularly.

If you follow the advice on this page your betta will live a long and happy life free of temperature shock.

To master the art of betta fish care, you need a comprehensive guide. Click here to read one!

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2 thoughts on “Betta Temperature Shock Symptoms And Treatment”

  1. If you do happen to put your fish in water that’s too hot what can you do to make things better

    • If you put your betta in water that’s too hot, you should siphon out some of the water, and replace it with cooler, conditioned water.

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