Guppy Temperature: Important Info To A Sustainable Habitat

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Last Updated: March 22, 2023 by Flora Gibbins

Guppies stand out as the most common tropical fish. They are not only colorful and vibrant, but they also get along well with other fish. Guppies are hardy species that can adapt to different water conditions, making them perfect for beginner tanks.  


If you are thinking of adding guppies to your community tank, you must learn about guppy temperature. 

What is the ideal guppy water temperature? What is the minimum water temperature? Do guppies need a heater? 

This article will provide answers to the above questions and more. Read on. 

What Is The Ideal Water Temperature For Guppies?

Guppies thrive in a tropical climate in the wild. The tropics are known for the warm water that guppies enjoy. So, when housing guppy fish, the tank water should replicate the same temperature found in their natural habitat.

The ideal temperature range for guppies is 72 to 82 degrees F (22-28 C). 

Should you dip your hand into the aquarium water, it should feel lukewarm. However, we recommend using a thermometer for accuracy. 

Guppies appear more active and healthy at this temperature range. Their colorful bodies are proof that they need warm water to thrive. Besides, they grow fast in warm temperatures. 

The optimal temperature for guppies fits the temperature range of other fish. So, you can keep guppies in a community aquarium with other tropical fish. 

What Is The Minimum Water Temperature For Guppies?

The ideal guppy water temperature should be between 72 and 82 degrees F (22-28 C). But what is the minimum water temperature for guppies? 

The minimum water temperature for guppy fish is 72 degrees Fahrenheit. 

However, these tropical fish are tolerant and can survive fluctuating water conditions for a day or two.

Guppies can survive in aquarium water temperatures of 65 degrees for a short period. But they are more prone to catching infections in these water parameters. It is safe to say that guppies can survive but not live in cold temperatures.

What Are The Effects Of Colder Water On Guppy Fish?

There have been reports about guppies surviving in water temperatures as low as 60 degrees. Unfortunately, numerous problems will arise from keeping your guppy in temperatures below 65 degrees F. 

It Makes Them Less Active

Cold-blooded animals are inactive in cold environments. Guppies are cold-blooded fish that need warmth for activity. Inactivity can cause your fish to become stressed and uncomfortable, sick, and die. 

Cold Water Makes Them Prone To Developing Diseases

Though hardy, cold water temperature makes your guppies more prone to catching diseases. These tropical fish are healthier in warm water than in cold water. If your guppies get sick, they can infect other fish in the tank, causing death. 

Cold Temperature Affects Breeding

Guppies need the energy to breed. Cold water makes them less active, sluggish, and lethargic. Their lack of energy makes breeding impossible. Moreover, guppy fries need warmer water to survive. 

Cold Water Slows Growth Rate

Did you know keeping guppies at the lower end of their optimal temperature range increases their lifespan?  Most fish owners keep their tank temperatures between 72 and 74 degrees Fahrenheit to slow the growth of their guppy fish for a longer lifespan. 

However, if you go below the recommended 72 degrees, your guppies may not grow fully as they are supposed to. This will affect the general appearance of your rainbow fish since guppies are colorful when fully grown. 

What Is The Maximum Water Temperatures For Guppy Fish?

The maximum temperature for guppies is 82 degrees Fahrenheit. Even then, these fish can survive in temperatures of 90 degrees. However, do not keep your guppies in such temperatures over long periods. 

Like cold water, high water temperatures also lead to adverse effects for your guppies. We recommend maintaining your tank water at 80 degrees and never above 82 degrees. 

Here is a YouTube video discussing the maximum water temperatures for guppies:

What Are The Effects Of Hot Water On Guppies?

Water temperatures above 82 degrees are too hot for guppies, and it often results in these two problems. 

Reduced Oxygen Levels

Most guppies die in hot water temperatures. Why? The warmer the water, the lower the oxygen level. Without oxygen, guppies cannot survive. 

Shorter Life Span

When guppies lack essential air to breathe, they die. Such deaths are premature since these fish can live for 2 to 3 years when their optimal water temperatures are maintained. 

In addition, when the water’s temperature is too hot, it promotes the growth of harmful bacteria and toxins. The toxins and bacteria can get your guppies stressed and sick. And since the water temperatures are not favorable, your guppies can easily die. 

If you observe that your guppies’ water is too hot, you can solve this by:

  • Using A Spray Bar

Add a spray bar into the filter to agitate the water surface. Doing so will increase oxygen level since warmer water has reduced oxygen. 

  • Use an Aquarium Fan

Also, add an aquarium fan to lower the water temperature. However, using a fan will cause evaporation. Therefore, remember to check the water levels and add water when necessary.   

  • Switch Off Aquarium Lights

Some aquarium lights produce heat and can increase the water temperature. Switching them off can help cool the water. 

  • Remove the Lid

Doing so can release the trapped heat and promote cold air circulation. Nevertheless, be careful if you have jumping fish in the guppy tank. 

Do Guppies Need A Heater?

We have established that guppies need a constant water temperature range to stay healthy, active, and happy. But do they need a water heater?

Yes. Guppies need a water heater. Aquarium heaters create the right temperature to keep these tropical fish healthy. 

What if your in-door temperature is always a stable 70 to 72 degrees Fahrenheit? Do you need a heater? Sure. This in-door air temperature is insufficient to warm the water in your tank. It turns out that water and air heat differently. 

When your air temperature is 70 degrees F, chances are the water temperature is lower than this.

The water heats up more slowly, unlike air. Due to this, you must get an aquarium heater. There are four common types of water heaters. See the following:

Submersible Heaters

Submersible Heaters

These heaters are meant to be submerged in water below the water line. They are made of durable plastic materials or fragile glass. For best results, submerge your heater at a vertical or horizontal angle. 

Hang-On Heaters

Hang-On Heaters

The hang-on heater is inexpensive and readily available in pet stores. These heaters are hung at the backside of the fish tank. They feature a heating element that is immersed in the water to raise the temperature. 

However, do not use these heaters in marine and salty aquariums. When salt makes contact with the heating element, it could cause corrosion or electrical shock. 

Substrate Heater

Substrate Heater

You install a substrate heater in the substrate. These heaters heat the guppy aquarium uniformly. Moreover, since they are installed in the substrate, they do not affect the tank’s appearance. 

Filter Heater

Filter Heater

Filter heaters are more suitable for bigger tanks. They heat the water as it is filtered back into the tank. Filter heaters also circulate heat evenly and are hidden from view. 

How Can You Maintain Water Temperature During Water Changes?

Guppy fish need a clean environment to thrive. This is why you should perform 25% weekly water changes. Water changes dilute excess nutrients to prevent cloudy and toxic water. 

You must maintain water temperature when performing water changes. The water temperature of the freshwater should be close to the water temperature in your fish tank. 

For instance, if the tank water temperature is 75 degrees F, you should set the fresh water temperature between 73 and 78 degrees Fahrenheit. Once you meet this water temperature, add the water slowly so your guppy fish can adapt slowly. 

Pay attention to chlorine levels in the freshwater, too. If your tap water has traces of chlorine, let it sit in an open container for 24 hours so the chlorine can evaporate. 

Can You Keep Guppy Fish In An Outside Pond? 

Sure. You can keep your guppies in an outside pond if you reside in a tropical environment. The water temperature in the tropics does not drop below 68 degrees Fahrenheit, even in the winter months. Moreover, you do not need a heater. 

However, if you live in a region that gets cold during the winter months, you can keep your guppies in the outside pond during the warmer seasons and then move them to an indoor fish tank during the cold months. 

The heat from the sun during summer and late spring will provide sufficient warmth for your guppies during the day and night. But once you observe that the water temperatures are below 68 degrees, consider moving your tropical fish indoors. 

What Is The Ideal Water Temperature For Breeding Guppies?

Guppies are well-known for their breeding proficiency. But for these guppy fish to breed every month, their water temperature should be correct. 

The suitable temperature for breeding guppies is 72 to 78 degrees Fahrenheit. These fish are more inclined to breed in warmer water than cold water. This is why some breeders raise the temperature in their fish tanks to promote breeding.    

The Best Time To Keep Guppies In Warmer Waters

The only time we recommend keeping guppies in warmer water is when administering treatments. If your guppy fish are undergoing treatments, you can raise the temperature above 82 degrees F.

It has been observed that these fish have improved response to treatment when in higher temperature water. Nevertheless, only keep them in warmer water temperatures for a short time since warm water has low oxygen levels. 

Where Should You Keep A Guppy Tank?

The best place to keep a guppy’s tank is a warm environment with a consistent temperature. Some aquarium owners choose to keep their tanks close to the windows or radiator. Both locations have their advantages and disadvantages. 

When you place a guppy’s tank by a window, the sun naturally heats the tank water. However, your guppies may be at risk of overheating during a summer heatwave. Fortunately, you can remedy this by closing the windows with curtains or blinds. 

Placing the guppy’s tank close to a radiator will also maintain warm water temperatures during winter. However, the same radiator will put your fish at risk of constant temperature changes. These aquarium fish are sensitive to water changes and can develop diseases. 

Fun Fact: There is a variety of guppy fish that require specific aquarium requisites. Learn about them by reading Types Of Guppies: 56 Fish Varieties To Keep You Preoccupied.

Frequently Asked Questions

What pH Level Do Guppies Like?

Guppies thrive in water with a pH level of 6.8 to 7.8 like other livebearers. They also enjoy hard water packed with minerals like calcium and magnesium. 

Which Other Fish Can Live In The Same Temperature Water As Guppies? 

Swordfish, angelfish, mollies, and platies are some of the fish that can live in warm waters as guppies. If you keep your guppies with these fish, ensure the minimum water temperature is 72 degrees and the maximum temperature is 82 degrees F. 

Which Water Temperature Is Best — Warm Or Cool ?

It depends. Warm temperatures are preferable for owners who want their guppies to grow faster. However, if you want your guppies to live longer, cooler water will promote a slower growth rate. 


The best water temperature range for guppies is 72 to 82 degrees F (22-28 C). We recommend maintaining the aquarium water temperature at this range even though these fish can survive in cold water or warm water.

In addition to keeping the guppies’ water at optimal temperature, feed them a healthy diet, perform weekly water changes, and check pH, ammonia, nitrite, and nitrate levels. Doing so will keep your fish healthy, happy, and active. 

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