Do Black Phantom Tetras Need a Heater?

Written By Lewis German  |  Tropical Fish  |  0 Comments

black phantom tetra

Black Phantom Tetras are great starter aquarium fish, however, they can often be misidentified as the similar looking Black Skirt Tetra, or Black Widow Tetra which is a different, more temperate species of fish.

Because of this mix up, newcomers can become confused as to whether or not the Black Phantom Tetra can be kept in a tank without a heater.

Can they? What temperature do Black Phantoms need to be kept at? And is a heater always necessary?

This and more we aim to answer below;

Can Black Phantom Tetras live in cold water?

Black Phantom Tetras are tropical fish, originating from parts of southern Brazil where it is very warm for the majority of the year.

Southern Brazil does occasionally receive cold spells throughout the year, especially during the winter time, but these dips seldom drop below 14C / 57F and tend to stay above 22C / 71F for the majority.

The waters Black Phantoms are from regularly stay above average room temperature, so while they may be able to withstand cooler weather on occasion, they are not true coldwater fish, and will struggle to survive in cold water.

Can Black Phantom Tetras live in a tank without a heater?

In some cases, where the outside temperature is warm enough, Black Phantoms can live without a heater.

However, we always recommend having one as a safety measure, as it allows you to provide the best possible care for your fish during times where the ambient temperature is not enough to keep the tank warm.

A heater provides you more control over the environment of your fish tank, and gives you the ability to respond to changes in the fish’s health by altering the temperature.

How long can Black Phantom Tetras survive without a heater?

Depending on the outside temperature, your Black Phantoms may live for a very long time without a heater, or they may struggle and succumb to disease quickly.

During summer, you may not need to use a heater for as long as the weather stays warm, but during the colder months, you need to pay close attention to the temperature, and to the behaviour of your fish.

Cold weather can dramatically impact the health of your aquarium, and a prolonged exposure to temperatures lower than 18C / 64F will lower the immune system of your fish and make them vulnerable to disease or other health problems.

It is advisable to not allow your tank to drop below this temperature for longer than 48 hours.

Why do Black Phantom Tetras need a heater?

Black Phantom Tetras need a heater because they have evolved in a tropical environment, and so are used to temperatures that regularly stay above average room temperature.

A heater allows you to better mimic the natural habitat of the Tetras to provide a healthy living space for them to thrive in.

Without a heater, you will have less control over the tank, and won’t be able to effectively respond to changes in the environment or in the fish’s health. 

You won’t be able to provide your fish with the best possible welfare.

What temperature should a Black Phantom Tetra tank be?

Black Phantom Tetras should be kept at tropical temperatures, ideally slightly above average room temperature, as this is where they are most comfortable.

They are able to live in slightly cooler waters on occasion, but they really prefer to be kept at a stable warm temperature anywhere between 22C / 72F to 27C / 81F.

From our experience in keeping them, we find they tend to do best at 24C / 75F. 

At this temperature, they are active but not overly boisterous, tend to have a good appetite and show excellent colouration.

When attempting to breed Black Phantoms the temperature can of course be increased to 28C / 82F, but be aware that they will need additional feeding at this temperature, and may be more aggressive towards each other, especially the males who will spar fiercely.

Types of aquarium heaters for Black Phantom Tetra tanks

Any type of heater will work with Black Phantom Tetras, but not every heater will work for every aquarium.

How you set up your aquarium will influence what type of heater will work best, tank size filtration and positioning are all important factors when selecting the type and size of heater you should use for your Black Phantom Tetra tank.

For most setups, a glass aquarium heater can be used, these heaters are versatile, easy to install and come in a multitude of different sizes, ideal for all different tank dimensions.

When choosing the right size, look at the wattage of the heater, and correlate it to the literage of the tank, so that it may match.

For example, a 50 litre tank needs a 50 watt heater, and so on…

Positioning is also very simple when it comes to glass heaters, as they come with a built-in thermostat that will switch the heater off when the water rises to the desired temperature.

For the best effectiveness, place the heater fully submerged in the tank, ideally stuck to the back of the glass or in the sump filter, where the most water movement is, and angle it 45 degrees.

For those larger aquariums, with sump tanks and very high amounts of water movement, a glass heater may not always do the job, and you may need to look for more powerful equipment.

Titanium heaters fill this role well, and are great at keeping those especially large tanks warm.

They work the same as glass heaters, but output much more heat, and tend to be much more durable.

Positioning and size works much the same, however, not all titanium heaters come with a built in thermostat, and you may need to install one separately.

When placing the thermostat probe, place it at the opposite end of the tank, so it may detect a more accurate temperature reading.

In a sump tank, place the thermostat / temperature controller probe at the intake side, this way it will detect the cool water entering the filter from the display.

Then place the heater near the outlet on the opposite end of the sump, so that it heats the newly filtered cool water before it re enters the display.

FAQs about heating Black Phantom Tetra tanks

How do you test the water temperature in a Black Phantom Tetra tank?

Testing the temperature of the water in your aquarium is as easy as using a thermometer and knowing how to read it.

But should you use just any type of thermometer?

Unfortunately not all thermometers are accurate, and not all are ideal in an aquarium setting, especially where the temperature is important in ensuring the fish’s health.

Accuracy and ease of use are important when selecting the right type of thermometer, which is why we like to use digital thermometers above all others.

They are very easy to use, and work by placing the LCD unit in the aquarium and sticking it to the glass, where the display can be seen at all times.

These thermometers are often battery powered, and will show the temperature in accurate, clear to read figures on a heads up display.

They are great as they show you the temperature constantly, allowing you to respond to any changes in temperature as soon as they occur.

Do Black Phantom Tetra fry need a heater?

Young Black Phantoms certainly need to be in a heated tank if they are to survive and do well, as fluctuations in temperature can stress their bodies too much.

At an early stage, Black Phantoms are extremely small, and lack the fat reserves to be able to cope with cooler water.

They are much weaker than the adults, so it is important that they are kept in a stable environment during this vulnerable developmental stage.

What happens to Black Phantom Tetras if the water is too cold?

Black Phantom Tetras are cold blooded, and depend on their environment to generate enough heat to fuel their bodies.

If the environment becomes too cold, then they will struggle to function properly, and will be unable to perform effective homeostasis, (which is to maintain balance in the body.)

Without this, the fish will quickly perish, so as a method of survival, Black Phantoms will slow down their bodily processes as the water gets cooler.

After the temperature drops a couple degrees past their normal comfortable range, they will begin to slow down, lowering their activity levels and starting to reduce some of their non essential bodily functions.

As the water continues to cool down, the fish’s digestive system will begin to lose functionality and they will be unable to effectively digest food properly.

Even colder and the fish will begin to suffer from organ damage, and if exposed to temperatures below 15C / 59F for over 48 hours, the risk of death is quite high.

What happens to Black Phantom Tetras if the water is too warm?

When kept in water that is too hot, Black Phantoms will increase in activity, as their metabolic rate speeds up with the heat.

They will expend more energy and will burn off fat quicker, needing to feed much more frequently.

They may also become more boisterous and aggressive, as the fish are more irritable in warmer water.

As the temperature continues to increase they will begin to struggle in absorbing enough oxygen, and may be seen at the surface of the water sucking air through their gills.

Once the water gets past 32C / 90F, they will suffer from organ damage, and eventually, heat stress will kill them if they are unable to cool down after a number of hours.

It is very important that you cool down the tank once it reaches past 32C, as this is a dangerous temperature for Black Phantoms to live at for very long.