Do You Need A Tank Heater For Guppies?

Water Temperatures Preferred By Guppies

Guppies can tolerate a wide range of temperatures.  There are articles on the internet that say that guppies can be kept in temperature ranges between 50°F and 84°F.

We find guppies do best for us in water temperatures between 72°F and 78°F.

Water temperatures below 72°F can slow growth and weaken guppies leaving them susceptible to illnesses such as Ich.

High temperatures can cause guppies to grow rapidly but will shorten their lifespan.

Is An Aquarium Heater Needed?

If you are lucky enough to live in a location where temperatures remain warm and relatively constant year round than you probably don’t need an aquarium heater.

For those of us that don’t live in a warm location the answer would be yes in most cases.  If your aquarium is subjected to temperatures that are below 72°F we would recommend using an aquarium heater.

Ideally aquarium heaters should be used also in rooms or locations that fluctuate in temperature rapidly or often.  For example aquariums placed near an exterior door or window may require the addition of an aquarium heater in order to prevent the fish from becoming stressed.

Whole Room Heat

Some hobbyists, especially those who keep a large number of aquariums heat the room the aquariums are kept in rather than the aquarium itself.  This works well if the room is well insulated so that temperatures don’t fluctuate too much or often.

A Word Caution

Probably the biggest reason we don’t always care for inexpensive aquarium heaters is due to their tendency to fail.  On more than one occasion we have had an aquarium heater fail and overheat the aquarium.

Preventing Disaster

There are a few things that can be done to help prevent losses due to a faulty aquarium heater.

Purchase Proper Size Water Heater

Water heaters are rated by wattage.  The larger the tank the higher wattage aquarium heater is needed.

There is a great aquarium heater calculator available online provided by Kerns Analysis Services.  The calculator takes into consideration a number of factors including what it is made out of and the difference between the room and aquarium temperature.

Note:  This calculator only works if the tank is covered.  Leaving your aquarium uncovered can reduce the water temperature and allows the water to evaporate more rapidly.

Buy A High Quality Aquarium Heater

Overheating can happen with many heaters that are available today however cheap, inexpensive heaters can increase the risk of your fish getting cooked.

Some modern high quality aquarium heaters feature integrated thermal protection circuitry designed to shut the heater off before it can overheat.

Plug The Aquarium Heater Into A Temperature Controller

Temperature controllers use a temperature sensor probe that is placed in the aquarium water.  When the controller senses the water is too hot the water it cuts the power to the water heater and prevents it from overheating the aquarium.

Follow Directions

Your aquarium heater comes with directions to aid in the safe operation of the heater.  Your instructions should help you find the best location to place your heater and give instructions on how the device should be installed.

Unplug The Aquarium Heater During A Water Change

If the water level gets too low in your aquarium it can damage your aquarium heater.  It is a fairly common occurrence for beginner hobbyists to crack the glass on their heater after allowing it to heat up outside the water level and then exposing it to water again.

Use An Aquarium Thermometer

Many aquarium heaters have a dial where the temperature can be adjusted.  The dial indicating the desired temperature setting is usually an approximation or can be completely inaccurate.

Using an aquarium thermometer in your tank can help to verify the water temperature is where you would like it and that the water temperature isn’t fluctuating too much.