What is an aquarium heater?
Fishkeepers use aquarium heaters to provide the optimal water temperature for fish and aquatic animals.
Heaters are used to maintain water temperatures. They can be used to simulate a natural habitat or to keep fish comfortable during the winter months.
Why is a heater important?
There are many different types of fish which have been collected around the world for the aquarium hobby. These fish have adapted to a range of different climates.
From deep open lakes to shallow muddy creeks, these native environments help us to understand what is needed to provide our fish with a comfortable environment.
When fish are not kept at a comfortable temperature it has different effects on their bodies which ultimately lead to stress. Stress is a huge factor in fish mortality so it is important we reduce it where we can.
Your fish can become less active and sluggish in aquarium water that is too cold. Their metabolism will slow and they will have less energy overall resulting in a weakened immune system. This makes them more susceptible to diseases and infection such as white spot or a fungal infection.
On the contrary, if your aquarium water is too hot your fish will become more active and have an increased metabolism. Fish will need more oxygen to operate in warmer temperatures as hotter water holds less oxygen. In extreme cases fish can suffocate.
Which fish need a heater?
There are many different temperature requirements for fish to be happy or to breed. For most of your common aquarium fish it is simplified into two categories, coldwater and tropical.
Coldwater vs Tropical
As a general guide, ‘coldwater’ is usually between 15°-20° and ‘tropical’ is between 23°-27°. There are many species that can operate outside of this guide so it is recommended to research the specific species you are wanting to keep.
These Fish can usually live happily without a heater however depending on location and time of the year, a heater may be needed to keep the water within a safe range.
In Ipswich, Queensland (where we are!) for example – temperatures can reach a low of 3 °. It is important to assess whether your water is dropping below the desired temperature so you can make the right steps to fix it.
These fish will generally need heating all year round to keep them happy and healthy. Even in hotter areas it is still recommended to use a heater to reduce any fluctuations; and therefore stress.
Whilst many of your common tropical fish thrive within a range of 23°-27°, there are some outliers which require higher temperatures if you are to find success.
Some examples of these are Ram Cichlids and Discus who prefer a temperature of around 29°
What types of aquarium heaters are there?
There are several different types of aquarium heaters such as submersible, hanging, in-line or in-filter.
Submersible heaters are the most widely used as they are more affordable and can be used in multiple different applications. Some submersible heaters also come with a protective guard. These guards not only protect the heater from damage caused by larger active fish but also prevents possible injury to fish which like to attach themselves to the heater such as Bristlenose Plecos or Sucker Catfish.
What size aquarium heater do I need for my tank?
Aquarium heaters come in many different sizes and are easy to choose if you know how many liters are in your tank.
A general guide is:
What brands of heater are there?
There are plenty of heater brands in the aquarium industry each bringing different features or price points to the market. Whilst some are cheap and affordable, others may have extra safety features or a longer lifespan.