Water temperature in a fish aquarium

Fish are cold-blooded creatures, their body temperature is determined by the temperature indicators of the surrounding space. The activity and viability of the fish depends on the comfort of the water. When the permissible degree is lowered or exceeded, the likelihood of illnesses in pets increases, but sharp temperature fluctuations are even more dangerous. There are different methods for normalizing the water temperature in a fish aquarium.

On temperature limits for warm-water and cold-water inhabitants of reservoirs

Tropical and subtropical regions are not characterized by frequent changes in water and air parameters. In Southeast Asia, the air temperature range is the same throughout the year, sometimes fluctuating within 3o Celsius (26-29 degrees), and the difference in water temperature is almost imperceptible. In South America it is hot and humid, with air temperatures of 25-28 degrees throughout the year.

There are species of fish that prefer wide temperature ranges, and there are those that live only in a narrow range. Only the fry of most fish are resistant to changes in to. When the amount of dissolved oxygen in the water decreases, all fish become less sensitive to temperature changes. Hydrobionts get used to high temperatures in a few days, and to cold temperatures in almost a month. For normal acclimatization, a gradual increase in to by 1-2 degrees and a decrease by 0.5-1 degrees is necessary.

All types of fish have their own upper and lower threshold to. Fish are sensitive to those parameters that go beyond acceptable limits. When the boundary is violated by a few degrees, the health of the fish deteriorates sharply. Frequent and sudden changes in temperature negatively affect the well-being of pets. To maintain optimal temperatures in the aquarium, you need to familiarize yourself with the permissible temperature conditions for warm-water and cold-water fish.

For warm-water fish, water below 18-20 degrees is considered unacceptable. Aquarium fish in this category are able to survive in lower ranges for a long time. But this fish requires a lot of oxygen and space, good aeration is necessary.

For cold-water fish, an unheated aquarium is suitable; 14-25 degrees is the maximum for them. They also need plenty of dissolved oxygen.

Thermometers

When kept in an aquarium, the water temperature requires careful monitoring. The possibility of sudden changes depends on the volume of the aquarium and the power of its heating or cooling devices.

Thermometers are used to measure the heat of a liquid. It is placed further from the heater, in the middle of the aquarium.

Thermometers come in 2 types depending on location:

Outer. Attaches to the outer wall. Due to the location, the measurement results have a large error. Because the thermometer is also influenced by the air, which is often colder.
Submersible (internal). It will be the best solution. Located inside the reservoir. The internal thermometer has a small measurement error and indicates a correct reading.

According to the type of action, thermometers are divided:

Glass thermometer with mercury reading.
Liquid crystal thermometer (self-adhesive strip on glass).
Digital Thermometer.
Alcohol thermometer.

Find out in advance what temperature should be in the fish aquarium.

Types of Aquarium Heaters

To make it possible to create the most comfortable conditions for the habitat of fish and plants, special devices are used - aquarium heaters. There are several types of them, but the principle of operation is the same for all - electrical heating of the element in a sealed environment. The most commonly used heaters are:

Submersible (plastic, glass, titanium). It consists of a heating element built into an impact-resistant, heat-resistant housing in the form of a flask or elongated cylinder, and is designed to be lowered into an aqueous environment.

Flow-through. It has a plastic body and is mounted in a vertical position on the return hose of an external filter, which saves internal space and creates a flow of warm, aerated water.

Heating cables. They are installed under the ground and allow you to evenly heat the entire aquarium and create additional water circulation.

Heating mats. They are rectangular mats that are installed under the aquarium. The heat generated passes evenly through the bottom and increases the temperature of the water.

It is generally accepted that sufficient heating device power should correspond to 1 W per liter, but in practice 0.7–0.8 W per liter is often used.

Aquarium heater with thermostat

The main inconveniences when using the heater are related to the need to constantly monitor its operation. Even having reached the desired water temperature, the device still continues to function and must be disconnected from the network manually. To get rid of this problem, a special device is used - a thermostat, which is a device with a built-in temperature sensor. It allows you to turn off the heating element when a preset value is reached and turn it on again when the water begins to cool.

This ensures a stable microclimate without temperature changes. The use of modern technologies makes it possible to produce very compact and easy-to-use thermostats.

According to manufacturing technology, they are divided into two types.

Electronic. They are highly accurate (most of them are equipped with an information board). Disadvantages include the relative high cost and lack of reliability.

Mechanical. They are found most often, are characterized by stability and reliability during operation, and are cheaper in price. They often distort real readings by several degrees, so to accurately adjust the device, you must use a separate thermometer.

According to the level of safety during operation and durability of the devices, thermostats are divided into:

Remote - located outside the aquarium, not affected by the aquatic environment and the waste products of aquatic organisms. This increases their service life and makes it possible to use cheaper heaters and replace them without additional costs. To determine the operating mode, a separate temperature sensor is used, which is located in the aquarium and connected by a wire to the thermostat.

Built-in - mounted in a sealed housing together with a heating element. With this configuration, the entire water control and heating system becomes very compact and easy to use.

The latter type of design is the most popular among aquarists and is often made in the form of an elongated glass flask, inside of which there is an electric heater and thermostat. For greater thermal conductivity, the space of the flask is filled with the smallest ceramic filler.

The tightness of the structure is ensured by a rubberized or plastic cap through which the power wire passes. There is also a regulator here that allows you to set the required temperature.

Well-known brands of aquarium equipment - Eheim, Fluval, Ferplast, Aquael, Tetra - produce reliable and high-quality submersible heaters for aquariums with a power thermostat from 25 to 300 W. Such devices are capable of providing the necessary conditions in aquariums up to 1500 liters.

To reduce the likelihood of water overheating, there is a practice of simultaneously using several less powerful thermal devices. If it is not possible to purchase the necessary equipment, you can make it yourself.

DIY aquarium heater

When making such a device, you need to remember that the operating conditions are associated with a serious risk of electric shock. But if the decision is made in favor of a homemade craft, then there is a good option to create a structure from resistors (resistance), a piece of glass tube with thick walls, dry filler and a remote thermostat. Installation work occurs in the following order.

1. The power of the heating element is determined based on a special table, which takes into account the difference in temperature between that required in the aquarium and room temperature. The required current is calculated by dividing the selected power by the applied voltage. By dividing the voltage used by the calculated current, you can obtain the resistance value of the heater. The required number of identical resistors is selected so that their total power and resistance indicator corresponds to the calculated values.

2. The length and diameter of the glass tube are determined based on the size and number of resistances. It is important that the resistors soldered in series are placed in the tube with a free space of 15 cm.

3. Cleaned and calcined sand can be used as a filler.

4. The bottom of the glass tube is closed with a suitable rubber stopper placed on the aquarium sealant.

5. The ends of the network cable are soldered to the upper and lower resistors. The entire structure is placed in a tube and covered with sand. It is important that the sand is at the bottom of the tube and covers the top resistor.

6. The top of the tube is carefully sealed with aquarium sealant. The power cable is connected to a thermostat with a remote temperature sensor, which in turn is placed in the aquarium.

7. The heater is placed vertically so that the part of the tube containing the resistors is hidden under water. The structure is attached to the wall of the aquarium using special suction cups.

Schemes for manufacturing the thermostat itself based on a comparator and thermistors have also been developed.

What should be the water temperature in a home aquarium?

In order for the inhabitants of home ponds to feel comfortable, the temperature there must be at a certain level. And before you introduce a fish into your aquarium, you need to know what the natural conditions of its existence are (and most aquarium inhabitants come from the tropics).

The gradation of temperature parameters can be represented as follows:

the optimal aquarium temperature, which is suitable for most fish, is in the range from 220 to 260C;
the water temperature in the aquarium below the minimum optimum is no longer acceptable for warm-water fish;
An increase in temperature above 260 is permissible by 2-40C if it is gradual.

Changes in temperature in a home pond in one direction or another from the optimal parameters are more easily tolerated by aquarium inhabitants if the water is sufficiently enriched with oxygen. It will be most difficult for well-fed fish - they require more air no matter the temperature difference. But with sudden cooling, hungry fish will also suffer.

Nuances

Is it necessary to replace the water in the aquarium with water of the same temperature?

Many tropical fish associate the addition of fresh, cooler water with the rainy season and the start of spawning. If you do not plan to breed fish, it is better not to risk it and replace the water in the aquarium with a liquid of the same temperature, or with a closer temperature.

For saltwater fish, it is imperative to equalize the water temperature, because there are no sharp changes in seawater.

How long does it take to acclimate a new fish?

Transferring fish from one aquarium to another is stressful for them. Fish that are improperly transported and transplanted may become ill and die. To avoid all this, you need to know what acclimatization is and how long it takes to acclimatize a new fish.

Fish acclimatization is a process in which fish are transplanted into a new aquarium with minimal changes in maintenance parameters. Acclimatization begins from the moment the fish are introduced into another aquarium.

It takes a lot of time for fish to get used to new conditions. If all parameters are met, acclimatization can last up to two weeks. It all depends on the reservoir, care and immunity of the inhabitants of the aquarium.

Ways to maintain temperature in an aquarium

As already mentioned, special means are used for a constant temperature value. These products are primarily intended for heating the aquarium. Experienced aquarists know how much room temperature affects an aquarium. The rest should remember ways to change the temperature balance of water at different times of the year:

not everyone knows that an aquarium refrigerator is used to lower the temperature;
if the apartment has an air conditioner, it will maintain the desired mode;
some fans blow a fan on the water surface;
if there is neither one nor the other, then ice can be used for cooling;
heating is carried out by a special heater;
when you don’t want to spend money on purchasing equipment, you can use a regular heating pad.

In any case, a person decides for himself what method he will use to heat or cool the water in the aquarium. Using professional devices, there is a guarantee of proper temperature control.

What to do if your water heater breaks down

Failure of the device can lead to overheating or hypothermia of water. In this situation, in order to restore the disturbed balance, you will have to act immediately.

Actions in case of hypothermia

When the water temperature drops, the fish become inactive and lethargic. In addition, their immunity decreases, which can cause illness. In this case, the broken water heater is replaced with a new one. If you don’t have a new appliance at home, you can maintain a comfortable water temperature as follows:

Pour hot water in a thin stream along the wall of the container, but under no circumstances boiling water. Thanks to this, you can raise the water temperature by 2-3 degrees, but, unfortunately, for a short time.
There is another way you can raise the temperature for a couple of hours. Take a plastic bottle, fill it with hot water and place it in the aquarium.

What to do if you overheat

First of all, increase the aeration. And after that you can do the following:

Place a plastic container with ice in the aquarium.
You can install a computer fan under the cover.
If you have an air conditioner, turn it on and lower the temperature in the room. The temperature in the aquarium will also drop by several degrees.

Why is the correct water temperature so important?

Fish are cold-blooded creatures, which means their body temperature always depends on the temperature of the environment. With an optimal indicator, the fish feel good, do not get sick and do not suffer from metabolic disorders. If the water is too cold, all processes in the body slow down, immunity sharply decreases, fish become sedentary and susceptible to any infections.

When the water heats up greatly, metabolic processes accelerate, the fish become very restless, begin to consume a lot of oxygen and experience a lack of it. In this case, they swim to the surface, frantically swallowing ordinary air. Death often occurs precisely because of oxygen deficiency. The health of aquarium inhabitants is even more affected by sharp shifts in one direction or another. Already with a difference of 3–4°, the fish develop a state of shock, which very often leads to death.

Definition options

To create comfortable living conditions for fish, you need to be able to monitor and determine the water temperature. To make this as convenient as possible, it is best to purchase a specialized thermometer or thermometer for an aquarium, which can have several varieties.

A mercury device made of glass is easy to work with, it accurately shows the increase or decrease in temperature, is easy to use and inexpensive. The main disadvantage is the destruction of the contents of the aquarium if the thermometer breaks.
An adhesive thermometer that looks like a strip. This is a liquid crystal device that must be placed on the outside of the aquarium, which leads to inaccurate data regarding the temperature of the aquatic environment; over time, the degree scale begins to fade.
An alcohol-filled thermometer is considered a budget option, convenient and inexpensive, but with a short service life, since after some time the readings will be inaccurate.
Electronic measuring instruments are the most convenient and multifunctional, they show accurate data, monitor any temperature changes and notify about them. The only drawback of such a thermometer is its considerable cost.

It is thanks to the constant monitoring of temperature indicators inside the aquarium that they can be adjusted and stabilized in time to reduce the negative impact on the health and vital functions of aquarium fish.

How to help fish with overheating or hypothermia

In extreme situations, when due to accidental failure of equipment the optimal water temperature may be disrupted, there is very little time left to save the inhabitants. Therefore, measures must be taken very quickly. But most often there is no spare heater at hand, and every minute counts. If the water has cooled down too much, you can warm it up a little by adding warm, but not hot, liquid so that the changes occur smoothly, by 2°C in 15-20 minutes.

But you can add no more than 10% of fresh water from the total volume of the aquarium. If the warming is not enough, then a plastic bottle of hot water lowered into a pond can help. In the most critical situations, when time is lost and the fish are so frozen that they lie on the bottom, barely showing signs of life, you can pour vodka into the water in a volume of 20-30 ml per 100 liters of container. Warming measures must be taken immediately. After the regime is restored, you will need to replace about 1/3 of the water to get rid of alcohol. Overheating is no less dangerous. An increase in temperature of 4°C from the usual is already dangerous for any species. The first aid in this case is maximum saturation of water with oxygen. You can turn on the aerator or mix the water by hand, add 20-25 ml of hydrogen peroxide per 100 liters of volume. A bottle of cold water in the aquarium will also help reduce the temperature. To prevent infections and parasitic infestations as a result of decreased immunity in fish due to hypothermia or overheating, broad-spectrum drugs should be used.

Is it true that cichlids tolerate different temperature ranges?

Cichlids require keeping in warm water, since this water temperature produces the secretion of enzymes for a rich body color and stimulates them to spawn. Cichlids have a high tolerance for both high and low temperatures, but not more than 6 hours. The tank can be maintained at a medium temperature range. When cichlids are kept at elevated temperatures, their color quickly becomes saturated, but they become exhausted and live less.

At low temperatures, the color of cichlids fades, and the fry grow and develop slowly. The permissible temperature for keeping cichlids is 24-30 degrees. The limit is 24-27 degrees. For Tanganyika cichlids, the water should not be warmer than 29 degrees. When treating certain diseases of cichlids, to is increased for a while.

Cichlids are truly one of the hardiest fish in the aquarium; for a novice aquarist, many representatives of this family will be excellent pets. However, all types of fish require careful care, which should not be forgotten.

Recommended number of degrees for each fish

Water temperature for aquarium fish is one of the important factors in the comfortable life and growth of pets. It is no secret that the number of degrees of water should be specific for each of the popular fish species:

Guppies - prefer to live at 23–26C. The lower limit is 14C and the upper limit is 30C. It is interesting that in cold water the size of guppies increases, but at the same time their immunity decreases.
Angelfish - optimal parameters vary from 24 to 27C. Limit degrees: 19 and 33. When the mark rises to 27C, the phenotype grows faster and reproduces more readily, but the lifespan of the fish becomes shorter.
Neons - in their natural habitat prefer warm water, so the best indicator is 23–25C. The lowest limit is 17C, the highest is 29C, but this shortens the lifespan of the fish.
Swordtails - the optimal number of degrees is 22-25.
Cockerels - an acceptable amount of heat is 23-25C.
Zebrafish – to keep zebrafish, the number of degrees should be 21–25.
Gourami – an environment between 22–26C is suitable for this species. Degree limits: from 20 to 33, however long-term maintenance in such conditions can be destructive.
Mollies – the best water parameters should be 25–27C.

Barbs - the phenotype has a wide range of content: from 20 to 27C.
Goldfish – acceptable thermometer readings are 20–24C.
Red-eared turtles are heat-loving creatures. The optimal number of degrees is 24–29C.

Aquarium fish require strict adherence to all maintenance parameters, including constant temperature control. If you do not follow the individual requirements of phenotypes, you can lose your beloved pet prematurely, or expose your fish to stress and discomfort.

Overheat

If the thermometer reading is above 30 degrees, then the inhabitants have a high probability of dying.

If there is excessive heating, the main thing is to lower the temperature in the reservoir.

Reasons why the environment becomes very warm:

Direct sunlight.
High ambient temperature.
Excessive proximity to heating devices.
Close proximity to a powerful lamp.
Incorrect reading from the water temperature control station for aquarium fish.
Lack of cover.

How to quickly cool water in a tank:

Pour cold liquid into a bottle and lower it into a superheated tank.
Point a fan at the surface of the liquid
Use an aquarium cooler or refrigerator.
Add ice to the water.

A dangerous consequence of an increase in thermometer readings is a lack of oxygen in the water. Pets will experience a lack of oxygen. The inhabitants swim up and try to breathe air from the surface. To saturate the liquid with oxygen, the liquid must be constantly aerated. To sharply increase the amount of oxygen, compressors, hydrogen peroxide and oxygen tablets are used. After a while, the fish will breathe calmly.

Hypothermia

When the room is ventilated and there are drafts, the temperature quickly drops.

To heat the liquid and maintain optimal performance, the following methods are used:

Using a heating pad.
Pour boiling water into the bottle and place it in chilled water.
Add boiled water from the kettle. Be careful when pouring boiling water. The percentage of boiled liquid should be below 10.
Use an aquarium heater.
Replace some of the water with warmer water. But this should be done slowly, and do not increase the degrees sharply.
Bring a powerful lamp to the surface.
Blow hot air onto the surface of the liquid.
Use a low boiler.
Catch and place the fish in an aquarium with warm water (if you have one).
Use alcohol if other methods are not suitable. Add 1 tablespoon per 100 liter tank. Don't forget to change the water afterwards.

Sudden changes

If fish are able to survive a low or high thermometer without any problems, then sudden changes will certainly cause illness. Pisces are sensitive to changes. The range of fluctuations of the thermometer should not be large in a short time. It often happens that when transporting fish it fluctuates greatly. In this case, many inhabitants will not arrive alive.

How to lower the temperature in a pond

A failed temperature sensor on the heating pad or close proximity to the heating system can cause a sharp increase in temperature in the aquarium. Even the sun's rays in summer will quickly warm a home pond if it is located on a southern windowsill. Try to ensure that the water parameters do not exceed 300C, otherwise the aquarium will turn into something like a cauldron with fish soup.

The same plastic bottle, but already filled with cold water or ice, can save the fish. The temperature should be lowered gradually.
Keep the compressor running continuously until the temperature can be reduced to normal. Increased aeration will allow the fish to breathe with “full gills.”
1 tbsp will also help enrich the water with oxygen. hydrogen peroxide (per 100-liter container). This pharmaceutical preparation will simultaneously disinfect the reservoir, destroying parasites.

It should be borne in mind that an increase in temperature is more contraindicated for aquarium fish than a decrease in temperature. Here, the poor health of aquatic inhabitants can also be affected by the presence of various nitrates in the water, which are especially harmful at elevated temperatures.

Monitoring and regulation

In order to prevent temperature changes, it is important to monitor the regime; this can be done using aquarium thermometers. They come in several types:

mercury;
liquid crystal;
electronic;
alcoholic.

It is best to choose submersible specimens, they are the most accurate. The thermometers are mounted on suction cups in the middle or closer to the bottom of the aquarium. Their only drawback is in the method of fastening, because the suction cups are often of poor quality, which means the device will fall. In addition, some fish themselves like to throw off the thermometer.

Water heaters are used for regulation. They look like a glass flask with a metal spring inside. At the top there is a lever and divisions; the heater must be set to the required mode and it will heat the water. But it is important to remember that when cleaning the aquarium, the device must be unplugged from the network, because it is prohibited to remove it from the water when it is turned on; it may burst.

The temperature must be monitored

Experienced aquarists have long protected themselves from such troubles as the need to lower or increase the degrees. To keep fish within optimal temperature limits, the following rules should be taken as a basis.

Choose the “right” place for the aquarium: away from heating devices, air conditioners, away from direct sunlight (especially in summer) and drafts.
The heating pad must be of high quality and have a reliable sensor.
A thermometer is a must-have device for any aquarium. Select its location so that it is convenient to monitor the scale indicators.
Aeration is not a fad, so the compressor should be turned on regularly. Without enough air, what kind of habitat would be comfortable?

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We remove differences

It is worth making sure that the temperature remains constant. To do this you need:

Use only a high-quality heater , and monitor its operation using a regular alcohol thermometer.
When making changes or adding water to replace the evaporated water, you should heat it to the temperature of the aquarium. For this, it is best to have another heater.
Do not install the aquarium near heating systems or kitchen appliances that emit high temperatures (ovens, multicookers, stoves).