Neon Tetra Temperature Guide (Do They Need A Heater?)

Whether you’re a fish fanatic or an aquarium owner, you have most likely heard of the famous Neon Tetra. Neon Tetras are colorful tropical fish originally from the streams of South America. However, given their popularity, they are now mostly bred in eastern countries such as China and Thailand.

For the Neon Tetra, temperature balance is crucial to maintain a healthy ecosystem. Not only is the temperature important for their health, but it is also a major factor in breeding as well. These temperatures do not usually come naturally in an aquarium, and a heater is usually required to ensure the tank stays warm throughout the day and night. If not maintained, the wrong temperature can have dire and even fatal effects on our colorful friends.

What Temperature Do Neon Tetra Need To Survive?

Given their origin in South America, it is not surprising in the least that Neon Tetras require warmer water to thrive. The ideal Neon Tetra temperature for survival is between 72 to 76 degrees Fahrenheit (22.2 – 24.4 degrees Celsius). And, for breeding, the Neon Tetra temperature should be between 75 – 76 degrees Fahrenheit (23.9 – 24.4 degrees Celsius).

They also require this temperature to be maintained consistently. It is very well possible that the aquarium temperature can rise and fall with the temperature outside of the tank as well.  And, while temperature change is indeed natural, it is when the temperature changes are quick and drastic that it starts to harm the Neon Tetra.

Do Neon Tetras Need A Heater?

One of the most important tools and pieces of equipment for Neon Tetra temperature balance is an aquarium heater. They are tropical fish, and therefore need to be kept in heated aquariums. While your aquarium may get to the desired temperature range for most of the day, most is not enough for our neon friends.

An aquarium heater is a necessary investment, and your Neon Tetra will thank you for it. There are a wide variety of heaters to choose from, and the type does matter. Different heaters have different wattages, and choosing the right heater for your tank is crucial. The different wattages are designed for different sizes of tanks.

When purchasing your heater, ensure you do the research to make sure you are getting the correct wattage for your tank. As a general rule of thumb, you should have between 2 .5 and 5 watts per gallon.

You also have the choice between pre-set and adjustable heaters, and which one you choose is entirely up to you and your specific aquarium. Once you have chosen your heater, ensure that you understand it completely. Some may shut off when removed from the water, which is particularly important to keep in mind when cleaning your tank.

Also, it is important to be aware that outside temperature can still affect the temperature of the aquarium, even with a heater. The heater can be set at a certain temperature; however, if the room temperature rises enough, it can also raise the temperature of the tank with it. The same also applies to cooling at night.

The Neon Tetra has no way of communicating with you if they’re feeling too hot or warm, and it’s up to you as the owner to ensure the tank is at the proper temperature at all times. Also, check on your tetras often, as there are usually signs or symptoms when something is wrong, or at least not quite right.

What Will Happen To Neon Tetras When It’s Too Cold?

So, what exactly will happen if your Neon Tetra gets too cold? Well—it’s definitely not good. Any temperature below 60 degrees Fahrenheit will put our little friend into shock and will almost certainly result in either death or permanent weakness.

And while these are the consequences of cold water, there are also adverse effects if the Neon Tetra temperature is too cool as well. Cool temperatures are classified from anywhere between 60 – 70 degrees Fahrenheit (15.5 – 21.1 degrees Celsius). Exposure to these temperatures will result in your Neon Tetra’s metabolism being slowed and can affect their digestion and even their breathing.

There are also a couple of other illnesses that either come from cool water or which are amplified when in cool water, including:

  • Fin Rot – an ailment that can be fatal to your fish. Their fins fist start turning colors—and, if left for too long, will begin to fall off entirely.
  • ICH – A parasite that causes havoc and damage to fish’s gills and skin.

    (Wondering whether your fish can survive ich without treatment?).

  • Neon Tetra Disease – Another parasitic disease that affects a large number of tetra fish. While not directly from cool water, the Neon Tetra Disease will capitalize on a weakened immune system caused by cool water.  The parasite primarily attacks and weakens the muscles, and becomes increasingly more potent over time.

Obviously, none of these are ideal, and you get the picture of just how and why it is so important to ensure Neon Tetra temperature is just right.

What Will Happen To Neon Tetras If It Gets Too Hot?

We have seen just how cold and cool temperatures affect the Neon Tetra—but what if it’s too hot? They are tropical fish, and although they are a bit more resilient when it comes to warmer temperatures outside of their preferred range, if it gets too hot, the effects can be just as devastating as when exposed to colder temperatures.

Too warm is generally any water temperature that is above 78 degrees Fahrenheit (25.6 degrees Celsius), and you can be sure issues will start cropping up when temperatures get to be around 90 degrees Fahrenheit (32 degrees Celsius).

And what exactly happens at these temperatures? A few things, which are also not very good for our little friends:

  • Oxygen Levels and Suffocation: a well acclimated tank has plenty of oxygen to go around. And, as you’re probably aware, fish breathe oxygen in the water. However, warm water will increase the Neon Tetra’s temperature and metabolism, causing it to become very hyperactive. This becomes a problem in that the more hyperactive the fish is, the more oxygen they consume. But that’s not all—warmer water actually has less oxygen, so it is a bit of a double threat to the Neon Tetra. A threat that can actually cause the Neon Tetras to suffocate.

How Does Sudden Temperature Change Affect Neon Tetras

How suddenly the Neon Tetra temperature changes is also an important factor in the health of your Neon Tetra. If temperature changes are necessary or inevitable, the single most important thing you can do for your Neon Tetra is ensuring that the change is slow and gradual.

Generally, sudden changes in temperature will result in a weakened immune system. This is caused by a combination of stress as well as changes to their digestion. Although the stress is usually temporary, the damage it can cause is irreversible. A weakened immune system further opens your tetra up to the risk of ICH and other bacterial and parasitic illnesses.

And, when it comes to drastic or sudden temperature change, it is usually dropping in temperature that is the most devastating. When the Neon Tetra’s temperature drops quickly – even if only for a short amount of time – they are highly likely to go into shock.

And, while this is not guaranteed to be fatal for the tetra, it will most likely be debilitating and drastically shorten their life span. Their muscles will become weakened, and they will undergo heavy stress. Similar to most animals, but especially fish, stress is like poison. Even a small amount of it can have adverse effects on their health and ultimately shorten their life span.

The same is true for sudden jumps in heat as well. The discomfort caused by the increased heat is enough to cause stress and may start affecting your Neon Tetra on a physiological level.

So, we know that the right temperature and warmth are necessary for a healthy and thriving Neon Tetra, so let’s take a look at how we can ensure we are maintaining this consistent temperature for our aquariums.

How Can You Make Sure Your Neon Tetras Tank Is Warm Enough?

One of the simplest investments you can make that can be a literal lifesaver for your aquarium and your tetras is to get a quality thermometer for your fish tank. This tool alone can indicate the slightest change in temperature, allowing you to respond in time before any significant harm is done.

There are a few options available to you, and some are indeed better than others, but for a higher cost. Here is a quick summary to help you choose what is right for you and your aquarium:

  • Stick on Thermometers (LCD): Although not the most accurate, they are accurate enough for general use. They are one of the cheaper options, and are most commonly used in freshwater aquariums. If you are looking for a reliable, inexpensive, and user-friendly thermometer, LCD thermometers may be the option for you.
  • Floating Thermometers: These thermometers are intended to be fully immersed in the aquarium in order to get a more direct and accurate reading of the water temperature. While accurate, they are still not as accurate as the digital alternative. They are also relatively inexpensive as well.
  • Digital Thermometers: Definitely the most expensive of the options, however, the advantages can be worth it. One of the biggest benefits is that most digital thermometers come with an alert of some kind to let you know if the water temperature is rising or dropping. This is definitely a game changer, and can make all the difference in the event of something going wrong, such as your heater failing.

Which thermometer you choose is up to you and your particular preference and budget. However, what is most important is that you have at least one of these options to ensure that your tank is maintaining the correct temperature at all times.

How Can You Keep Your Tank Warm Without A Heater In An Emergency?

So, say you chose the digital thermometer with the audible alert function. You are enjoying a calm and casual evening, watching television or reading a book. Then–all of a sudden, you– receive an alert. You go to check and see that your heater has quit working entirely.

You can see from the digital display that the temperature is dropping fast. You don’t have a backup heater, and nothing is open. It is going to be night soon, and as the temperature of the room drops, the water in the tank will plummet even faster.

Don’t panic. Here are some temporary measures you can take to keep your tank warm In the event of an emergency:

  • Protect the Filtration System: Wrap it in linen or to protect it.
    Cover the Outside of the Tank: Cover both the outside of the tank with a thick blanket. This will assist in preventing heat from escaping.
    Cover the Tank with a Lid: This is another way to slow the loss of heat in the aquarium.
    Heaters: Utilize your household heaters by keeping it near the fish tank. This can help slow the loss of heat as well.

There are many other reasons why you may need to keep your tank warm other than the heater failing. That is why it is best to make sure you are prepared for anything. Having a backup generator and backup heater are some ways that you can be much more proactive in the event of an emergency.

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Neon Tetra temperature makes all the difference in both their health and comfort. If properly kept and supported, Neon Tetras make for some of the best and beautiful aquarium fish to keep. However, to properly care for them, you will need to ensure you have the right equipment to maintain and monitor the right temperatures. The very basics include a thermometer and a heater to ensure that the water temperature is warm (but not too warm!). The investment will be well worth it, and your tetras will thank you for it!

If you liked this article, make sure you check out the rest of the website! And if you have any more questions, you can ask them in the Q&A Section!

2 thoughts on “Neon Tetra Temperature Guide (Do They Need A Heater?)”

  1. Hi it’s currently 31*C here and tank is getting to warm. What is best way to cool a tank? It’s going to be warm for few days.

    • Hey Luke,

      You can actually get fans that sit on the top of your tank and blow over the water to keep it cool. Or a regular desk fan can do the same job. Also try to keep your tank out of direct sunlight

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