Setting up an aquarium is an art as much as it is a science and when setting one up there are so many decisions that you need to take, for instance, the lighting of the aquarium, the plants, the gravel and the filter. However, many times, we tend to overlook a very vital aspect of the aquarium setting and that’s the aquarium heater.
A fish tank heater or an aquarium heater is equipment that raises the temperature of the water and helps to keep the water in the tank at the desired level and prevents it from falling below a specific temperature.
An aquarium heater is required if the fish is kept in a room where the temperature is below the temperature required for the particular fish or if the temperature falls below the minimum point, which is not conducive for the fish.
The most important aspect of the temperature of the water in the aquarium is stability and on a daily basis, the temperature of the water in the aquarium must not change more than 1-2 degrees.
In This Article You Will Learn…Why Your Aquarium Needs A HeaterWhat Types Of Fish Need Heated Water?Types Of Aquarium HeatersGlass Immersion HeaterUnder Tank HeatersUndergravel HeatersSubmersible HeatersFilter HeatersHow Aquarium Heaters WorkHow Precise Are Aquarium Heaters?Preset HeatersNon-Preset HeatersMaintenance Of Your Aquarium Heaters
Why You Needs An Aquarium Heater
Fish are essentially poikilothermal and cannot produce body heat on their own, unlike mammals and human beings.
And, they usually rely on the water temperature, whether in the sea or the aquarium, to keep their body temperature regulated, which changes according to the surrounding environment. Usually, the water temperature of the oceans and seas is more or less the same during different times, so the fish survive in their natural habitat easily.
Since the aquarium is not a natural habitat for the fish and is man-made, maintaining the temperature of the water in an aquarium is very important, which is why a water heater becomes an extremely important accessory when setting up an aquarium.
Maintaining the temperature of the aquarium is the key to keeping your fish comfortable and is also very important for their health and well-being. And, as much as the other factors such as the water filtration, pH balance of the water and adequate nutrition are important, water temperature is also vital for the health of the aquarium fish.
If the temperature of the water falls below a particular range, the fish become inactive, sluggish and will stop eating. And, before long, the fish will die due to starvation if not because of the cold.
Sometimes, when the temperature of the water falls below the ideal range, your fish may eat and behave normally; however, in the long run, their immune system will get weaker and they will become sick and die.
Fluctuating water temperature can also lead to an outbreak of ich, which is an aquarium disease caused by a parasitic infection. This causes the appearance of white spots on the fish, and if untreated, this can be quite lethal.
So, it is very important to keep the temperature of the water in your aquarium conducive for your fish to flourish and thrive. And, to keep the water temperature in the aquarium stable, you need to install a water heater. And, along with the heater, it is a good idea to install a thermometer in the aquarium too to get an accurate reading of the water temperature.
It is very important to keep the water temperature of your aquarium regulated and maintained at the same level, in both, day and night. Even a variation of 1-3 degrees can cause the fish serious health problems.
What Types Of Fish Need Heated Water?
According to the kind of fish you are keeping, freshwater fish may or may not require heat. Cold-water fish do not need a heater; however, not all kinds of freshwater fish can live in cool water.
Freshwater fish can be classified as tropical and sub-tropical. While tropical fish need heat to survive in temperate conditions, sub-tropical fish can subsist in cool water as long as the water does not become too cold.
As a general rule, tropical and marine fish require an aquarium heater, while temperate fish do not really need an aquarium heater. Tropical fish usually need water temperatures between 74oF- 82oF (23oC-28oC) to survive. Some examples of freshwater tropical fish are black shark, blue danio, black neon tetra, banjo catfish, angelfish, bala shark, Australian rainbowfish, etc.
Freshwater non-tropical fish can withstand a wide temperature range, are quite hardy and can live even without an aquarium heater. Fish like goldfish can be kept outdoors even in temperate climates. Examples of non-tropical freshwater fish are pufferfish, goldfish, common guppy, koi and clown loach.
And, since the water temperature needs for both tropical and temperate fish are different, you cannot keep these two varieties in a single aquarium.
Some fish have a very narrow window of temperature tolerance and require that the heater keeps the water temperature regulated within ±1°F. However, some fish can withstand a wider range of temperatures. Nevertheless, all fish are extremely sensitive to the changes in water temperature.
Types Of Aquarium Heaters
Just as tanks are available in various sizes and shapes, you also have different kinds of aquarium heaters available with varied features and you need to decide on one that is right for the kind of fish you have and based on your aquarium setup.
Glass Immersion Heater
The glass immersion aquarium heater is also known as the hanging heater, they are the most common heaters used by hobbyists. These heaters are quite popular and they are the most inexpensive options too. These are immersion-style heaters, which comprises a glass tube with a heating element that is coiled around a glass or ceramic insert.
The glass tubing contains a thermostat which is adjustable. It turns on the heating element so that the temperature of the water is maintained at the required level. The thermostat is essentially a bimetallic strip, which consists of two different metals. When the temperature rises, the 2 strips expand at varied rates and causes it to bend.
The strip carries the electric current and as the desired temperature is reached, the strip breaks the current. You can make adjustments to the setting of the bimetallic strip according to the temperature you require.
The more modern glass immersion heaters make use of microchip technology to control the temperature. The heater also has a small light to indicate when it is in operation. Glass immersion heaters are not quite suited for use in marine and brackish water aquariums, as the heater can get corroded if the water gets into the tube.
Under Tank Heaters
Under tank heaters are essentially heating devices that are used for glass aquariums housing amphibians and reptiles. The under tank heater is made of flat plastic and metal, and looks like a heating pad. The heater is usually placed on the underside of a terrarium or an aquarium.
When using an under tank heater, you must use a substrate in the aquarium and the heater must be hooked up to a rheostat or a thermostat to ensure that it does not get overheated, which may increase the risk of the animals in the aquarium getting burned.
The heating mats can also be placed under the aquarium; however, this method of heating is not very efficient as glass is a poor conductor of heat. You need to be cautious when using an under tank heater and check it for wear and discoloration, and the temperature also must be monitored very carefully. The under tank heater can result in high temperatures that can kill the animals and may even start a fire.
Undergravel Heaters
As the name suggests, substrate heaters or undergravel heaters are placed below the gravel and there is no visible hardware that can be seen. Undergravel heaters comprise a grid or coil of wire enclosed in an insulator or a heating cable that is buried in the substrate or the gravel, lining the floor of the aquarium.
The coil of wire is the heater element and when the heater is switched on, the wire gets heated and, in turn, heats up the gravel in the aquarium. The heat radiates from the gravel, heats up the water and when the water turns sufficiently hot, the thermostat shuts off.
Substrate heaters are effective, as they heat the water in the aquarium more evenly than other kinds of heaters. These substrate heaters are especially advantageous in the case of tanks which have plants and the gravel acts as an insulator, keeps the roots of the plants cool and also encourage the growth of the plants. Undergravel heaters help to keep the water in the aquarium and the fish nice and warm while keeping the plants cool and comfortable.
However, in spite of all these advantages, substrate heaters are not the most common kind of heating equipment and not very widely used for hobby aquariums, as the aquarium needs to be completely dismantled in order to install the heater and also in case of any problem, you need to take apart the entire tank to replace the cable or repair it.
Submersible Heaters
These heaters can be completely immersed in the aquarium water and these aquarium heaters are more efficient as compared to the hanging type of heaters. These heaters are quite popular among hobbyists, as they are quite inexpensive and also extremely easy to install.
Submersible heaters can be placed quite deep into the water and can be placed in any angle you wish or even in the horizontal or vertical position.
If the submersible aquarium heater is equipped with an internal thermostat, then it works better when placed horizontally in the aquarium and fairly low in the water. This helps to get a more precise reading of the temperature of the water in the tank and it will also help to activate and shut off the heater more efficiently.
Usually, submersible aquarium heaters are attached behind the aquarium with the help of suction cups. It is essential that you keep the heater away from the gravel, as the heat difference between the gravel and the water can cause the glass of the heater to crack.
Also, you must provide sufficient space on the side of the aquarium or between the gravel and heater to ensure that no fish get caught between the heater and get burnt.
The only drawback of the submersible aquarium heater is that if there is a malfunction, it is difficult to repair the heater and since the heater is mostly made of glass, it can break easily if attacked by large-size fish.
Filter Heaters
These aquarium heaters are the latest type of heaters in the market and if budget is not the constraint, then these heaters are the perfect choice for your aquarium.
Filter aquarium heaters are usually placed in the filter of the aquarium and when the water passes through the filter, it gets heated.
This way, there is no heating equipment that is placed inside the aquarium, which makes it quite attractive for fish keepers. The filter aquarium heaters are also ideal for large-sized tanks that have huge volumes of water.
How Aquarium Heaters Work
Fish are quite delicate and sensitive to the environment. The fluctuating temperatures of the water, which is too cold or too warm, can cause the fish great stress. The water conditions should be stable throughout the day and should not rise by day and dip by night.
In order to keep the temperatures from fluctuating, it is a good idea to use aquarium heaters with thermostats that will keep the temperature constant. You can either connect the thermostat to the heater separately or these days, you can also buy a more advanced model with an inbuilt thermostat that can be set to the required temperature.
Most of the heaters come enclosed in glass tubes, although these days stainless-steel and titanium heaters are becoming quite popular because of their unbreakable and sturdy design.
Some of the aquarium heaters have warm-cold adjustments and you need to adjust this till the aquarium water reaches the required temperature. Other models can be set in degrees so that you can set the precise temperature and other heaters have preset temperatures you can choose from.
Usually, the rating of aquarium heaters is in watts and the manufacturers specify the size of the tank for which the heater is designed. Normally, when you select a heater for your aquarium, 5 watts for 1 gallon of water is adequate. So, for a 25-gallon tank, you would need a 125-watt aquarium heater.
Ideally, for an aquarium placed in a room with normal temperatures, you would require a 100-watt heater for 20-gallons, a 300-watt heater for 100-gallons of water and so on. However, if the room gets very cold, you would need to use a heater with a higher wattage. The objective is to keep the water temperature as stable as possible.
However, in conditions where you have dry/wet filters, where the flow rate is high or where the temperature falls below 55o, then you may have to get a heater of 5-8 watts per gallon.
The 5 watts per gallon is quite a conservative estimate, especially when you consider big tanks in homes that are centrally-heated, since large tanks tend to lose heat slowly as compared to tanks that are smaller in size.
Also, if your fish tank is large, it is a good idea to have 2 heaters so that the wattage is split. For instance, for a 50-gallon tank, you could have 2 heaters of 100 watts. This is especially beneficial if the thermostat fails and the heater remains, you can save your fish before they die due to overheating.
If one of the heaters fails, at least the other one will be able to maintain the aquarium temperature partially until you notice the problem. These days, some modern aquarium heater models come with an alarm that will give you a warning if the thermostat fails.
How Precise Are Aquarium Heaters?
Although aquarium heaters are quite commonly used, often people are confused about how to set them and wonder how accurate these heaters really are.
Older aquarium heaters did not have any markings on the dial and you needed to just turn the heater and adjust the water temperature until the light came on and then you needed to make adjustments till you had the desired water temperature.
These days there are 2 types of aquarium heaters available – preset heaters and non-preset heaters.
Preset Heaters
There are several models of preset aquarium heaters available in the market, which feature a temperature gauge on the control knob of the heater or at the side, which allows you to set the temperature.
This helps to get the thermostat to the right temperature range; however, these are not too accurate.
Though most manufacturers claim that these thermostats are accurate; however, they are usually accurate within 2-3oF (1-1.5oC) and over the life of the heater, the accuracy declines. So, it is important to keep this in mind and monitor the heater and adjust the thermostat whenever required, rather than assuming that the heater markings are precise.
Some preset heaters make claims that they are factory set to the correct temperature and do not need any adjustment.
These kinds of heaters should ideally be avoided as there is no way that the heaters can set the water temperatures accurately, as some fish need warmer water and some prefer cooler water, and many times in the case of the fish contracting a disease, you will require increasing the temperature in order to kill the disease.
Having a heater for the aquarium without an adjustable thermostat means that you cannot adjust the heater when there are power spikes or when the heater and the components age and become less effective.
Non-Preset Heaters
These heaters are inexpensive compared to the preset heaters. If you decide to buy a non-preset heater for your aquarium, avoid setting the thermostat until the heater is set up inside the aquarium and the thermostat can be properly adjusted and monitored.
Although the non-preset heaters are not already set, they are fairly accurate and are usually set to the proper temperature.
Maintenance Of Your Aquarium Heaters
It is a good idea to do some homework about the fish you plan to keep, the kind of aquarium you want and what are the requirements for an attractive aquarium with a conducive environment for your precious pets.
The main goal should be that the fish in your aquarium are happy and healthy. And for this, it is of utmost importance that the temperature of the water in your aquarium is stable, which is possible when you have a good water heater.
There are many heater models that you can choose from, so it is a good idea to evaluate the various options available and their features before you determine the best one for your home aquarium. We get into the depth of all of this and more in our buying guide for aquarium heaters, so check it out if you’d like to know more!
Resources:TheSpruceFirstTankGuideFish-Tank-AquariumswikiHowMyAquariumClub