When I used to be a moderator in a large aquarium Facebook group, I was always debating with people on the topic of cold water fish and so-called warm water fish. Many people like to call Goldfish cold water fish while referring to any tropical fish as a warm water fish.
The truth is, for many tropical species of fish, room-temperature water is within the temperature range they prefer. So do you really need an aquarium heater? Let’s discuss this age-old topic.
Species Specific Needs
The answer to the question is actually very straightforward, you need to look at their natural habitat. Some species will come from very warm water, while others do not. This is even true for what you would call tropical fish.
Goldfish, for example, are temperate species who can flourish in a wide range of temperatures, from hot summer conditions to even an icy winter. This is the reason they are so highly invasive, they can survive and reproduce in most climates. This means that a heater is not required for a Goldfish.
In contrast, a Blue Ram Cichlid comes from the warm shallow waters of Venezuela and Colombia, where temperatures can reach 90F (32C). Therefore, room temperature water, unless you don’t have air-conditioning and live in a hot climate, won’t be warm enough for them.
Aquarium Heaters: The Verdict
Whether you need an aquarium heater comes down to the specific species. You should always research the specific needs of a species before purchasing them.
