Last Updated on April 24, 2023 by Coral Realm

Guppies (also known as Rainbow Fish or Millions Fish) – A Favorite all-rounder for the Aquarium, but can they Survive in an Outdoor Fish Pond?


Guppy Pond 2020 Guide

Guppies in Outside Ponds - Guppy Pond Guide

Guppy Facts

The Guppy (Poecilia reticulata) is a native of South America, originally discovered in Venezuela, and is a very popular breed. 

It is a good-natured, low-maintenance species of fish which will cohabit in the aquarium very happily with many other species, including Platy Fish, Molly Fish, Tetras and bottom feeders such as Clown Loaches and Plecos.

Being easy to manage and without complex requirements these busy, energetic little fish are a good start for the novice aquarium keeper, but also make a good addition to the fish tank of the experienced fish keeper.

In the wild, Guppies are quite plain in appearance when compared to their aquarium counterparts. This is because they have been selectively bred commercially on a huge scale in order to produce a range of colors and fin shape.

It is the males of the Guppy species which have the brightest colors and the long fan-shaped caudal fin, but both males and females are great within the aquarium environment.

It is a fact that male Guppies work hard to keep the attention of the females, and will chase them endlessly around the tank. Hoping their colorful bodies and tail fins will impress the females and give them a chance to mate, it can become a continuous quest.

Unfortunately, this can stress and exhaust the females, so it’s important that females outrank the males in terms of numbers so that all this attention can be spread around the female group. Ideally you would have two females for each male within the aquarium – a 2:1 ratio.

Numerous varieties are available, and they are classified according to their physical characteristics, including color, patterns and tail formations.

One characteristic of the Guppy, which can be both a blessing and a negative, is that they are prolific breeders with no intervention required from the aquarist. Their alternative name of Millions Fish has been coined in recognition of this breeding success! 

They are in the category of live-bearers, which mean they produce live fry rather than laying eggs.

Simply putting both male and female of the species together in the tank will result in batches of fry being produced on a regular basis. We have been called out to homes on several occasions where Guppies have taken over the aquaria!! 

Guppies breed readily and plentifully, so can soon overcrowd the tank and create a problem.

Aside from trying to find alternative homes, people have asked us whether Guppies are candidates for life in a garden pond. 

Can Guppies Thrive in an Outdoor Guppy Pond?

So the question is: Can Guppies live outside in garden ponds?

A simple question, but not a simple answer. 

We must remember that Guppies are tropical fish so the temperature is important – between 72 and 82 degrees Fahrenheit will suffice for a Guppy, and for very short periods of time they can manage as far down as 65 degrees Fahrenheit, but we would not advise this for long.

In short, Guppies can survive in these lower temperatures but they will not flourish and thrive in such harsh conditions. 

We reiterate – Guppies are tropical fish and this must be respected if your fish are to live happily in captivity.

If you live in an area where the temperature is stable all year round and does not drop below 68 degrees Fahrenheit or 20 degrees Celsius, then your Guppies will live happily in an outside pond with the need for additional pond heating or the job of transferring them to an aquarium during the colder winter months.

Obviously, if you have varying seasons in your locality and the warmer months provide the correct temperature range for the Guppy, then they can live in an outdoor pond for those times, but will have to be transferred to a heated aquarium during the colder months. 

Using a heater in an outside pond is uneconomical and it’s difficult to precisely regulate the temperature as effectively as within the aquarium environment.

This is very time consuming and impractical, as the Guppies will breed in the outside pond and therefore require increasing aquarium space.

We are highlighting the downside to encourage careful thought before putting Guppies outside in a harsh environment, but they are hardy and adaptable and will enjoy the space of a larger outdoors pond and the natural environment such a setting provides. 

Guppies feed on algae and will happily consume mosquitos that find their way into the pond, and will enjoy this activity in the outside pond.

Author’s Note: Our straightforward advice is that Guppies will love an outside guppy pond, but only if you live in the right climate, as stated above or are prepared to take the necessary steps to protect them when the temperature falls.

Guppy Varieties and Other Facts

The little Guppy is a tropical fish that is very popular with aquarists and fish keepers, as they are straightforward to keep. They are colorful and energetic, with a friendly disposition and, as such, make good tank companions for many other species of fish.

As we have already highlighted above, one main area of consideration with the Guppy is that they are prolific breeders, and your aquarium can soon become overcrowded as live fry are continuously produced. Do beware of this, and ensure that you have more females to males (2 to 1 ratio is best) in order to prevent excessive stress on the females.

There are many different types and varieties of Guppies with different colors and fin shapes, and breeders are always trying different breeding selections to create new varieties. On account of selective breeding programmes, many color variations and tail types have emerged. 

Guppy types vary in terms of color, fin type and pattern, and they can be found in a huge range of colors. Some are quite shiny and iridescent – quite metallic in their hue.

It is quite common to see Guppies with different colors on the head and tail ends of their bodies, usually with a lighter color on the upper section.

Sociable and easy to keep, Guppies are a great addition to the community aquarium. 

Quite robust, they can be kept in outside ponds as long as the temperature is fairly consistent throughout the year and doesn’t drop below 68 degrees Fahrenheit. Temperature fluctuations below this level will result in them needing to be transferred to a heated aquarium during cold spells, which is time consuming, but in the right climate, Guppies do really well and thrive in an outdoor setting.

Setting Up Your Guppy Pond

Guppies make a wonderful display in a garden pond or patio tank, but to reiterate – please remember that Guppies are tropical fish and need consistent temperatures of between approximately 72 and 82 degrees degrees Fahrenheit.

Guppies will survive a very temporary drop in temperature of one or two days down to 65 degrees, but this must really be for a short time period.

Some fish enthusiasts do install heaters to an external pond, but this is not economical and it can still prove difficult to regulate the temperature if the climate is simply too extreme.

Whilst there is an obvious correlation between air temperature and water temperature, water in the exterior pond will heat up and cool down at a slower rate than the air temperature, so the water in your pond will not match the extremes of the air temperature.

You will need to ensure that your pond is sufficiently deep to ensure that the water doesn’t heat up too quickly. Between one and two feet in depth should suffice, but all the better if you can provide areas in the pond that are deeper still. Include too some shallower areas for interest.

Of equal importance is that the pond is not entirely in direct sunlight – shade, at least partial shade, is of paramount importance. Having a shaded pond will also help in attracting pond frogs.

There will be a temperature differential between the deeper and shallower areas of your pond, so it’s advisable to take the temperature at regular times throughout the day, comparing the different depths as well. This will help you assess whether you need to provide more shade.

A further aspect of your initial pond set up is the inclusion of a filtration system and a method of aeration, such as a fountain or other water feature or an air pump which pushes the water round and agitates it sufficient to create air flow. Your planting will assist with oxygen levels, but are not sufficient on their own.

Another vital component of your pond design is the planting within your garden pond. Floating pond plants and other aquatic planting not only provide shade and some protection from predators, they will also give the tiny fry places to hide at the stage when they’re vulnerable to becoming a meal for the other Guppies!

Not only are aquatic plants a beautiful and aesthetically pleasing addition to any garden pond, they provide a vital service for the health and sustainability of your pond. They filter waste from the water and provide a vital boost to oxygen levels, whilst creating interest and a safe-haven for your Guppies.

Similarly a good fish pond filter with triple stage filtration is advisable to provide a clean and safe habitat for them.

If practicable, we would suggest covering the pond with netting. Guppies love to jump! Whilst the precise reason for this is not well understood, and many theories have been purported, the fact is that they have been known to jump from aquaria and ponds, so netting is a necessary solution.

A stout net covering will also protect your Guppies from predators, giving you peace of mind.

When stocking your pond, remember that whilst Guppies are friendly and cohabit well with many other fish species, avoid keeping them with larger predatory fish.

Feeding Your Guppies

Guppies are omnivores, enjoying eating animal protein as well as plant based material.  

Guppy mild case of spinal deformity

Guppy with a mild case of spinal deformity

Guppies can suffer from conditions which adversely affected their physical development, such as scoliosis and lordosis – see the photo to the right.

This unfortunate situation arises from deficiency in the mineral phosphorus, which aids bone development and growth, so a diet balanced with minerals is important. 

Whilst phosphorus is the most vital mineral for Guppies, other important minerals for this fish species are calcium, iodine, iron, copper, magnesium, zinc, selenium and even manganese. 

Guppies feed on algae and will happily consume mosquito’s that find their way into the pond, and will enjoy this activity in the outside pond. They have even been relied upon in certain areas of the world as a contributing factor to the control of mosquito populations.

Although your Guppies will find lots to eat within an established pond, it is always good practice to feed them pellets specifically designed for Guppies. This will ensure your fish get the correct balance of minerals and other essentials within their diet. 

Feed your Guppies once or twice daily, and observe how quickly your fishes consume all the food. Adjust the amount given at each sitting if the food is not being consumed within approximately three minutes to avoid polluting your pond.

Feel free to give some finely chopped ‘greens’ sometimes too, such as spinach, kale and crushed fresh peas. Not too much though as uneaten food may start to rot at the base of the pond.

We feed our aquarium Guppies bloodworms which they absolutely love, and these can be provided within the pond environment too but, again, remember to be careful not to give too much at once.

Areas of Concern with Outdoor Guppy Ponds

As we have mentioned in the previous section, a main area of concern with any outdoor pond is temperature control. 

Ensure your pond is not entirely in direct sunlight – shade, at least in some areas of the pool, is of vital importance. 

Your exterior pond should also be sufficiently deep to avoid excessive heating or cooling within very shallow depths – a pond between one and two feet in depth with areas of greater depth too will be ideal. 

If you are short of natural shade in your garden, the pond can be partially covered with fiber-board or other material to provide a cooler zone. 

Again, as previously discussed, Guppies love to jump! Covering the pond with fine netting, together with the solid board for provision of shade, will prevent them jumping completely out of the pond.

The coverings will have the additional advantage of protecting your Guppies from predators.

A fine mesh or netting will catch any falling leaves or other natural matter that would otherwise fall into the pond, creating unhealthy mulch on the bottom of your pond.

Some mosquito’s will still find their way through the netting, so your Guppies won’t be short of mosquito larvae to feast upon – their favorite food stuff!

A final note of warning! Keep an eye on your Guppy numbers! We’ve mentioned several times in our previous sections – Guppies are prolific breeders. Whilst they will inevitably have more space in an outside pond environment that within an aquarium, you’ll still need to keep pace with their numbers to avoid overcrowding.

Guppy Pond Outdoors


The Guppy is a good-natured, low-maintenance species of fish which will cohabit in the aquarium very happily with many other species. Its ease of maintenance makes the Guppy a very popular choice amongst fish keepers – from the beginner through to the experienced aquarist.

Classified according to their physical characteristics, including color, patterns and tail formations, Guppies come in a wide array of varieties and provide the aquarium with a stunning display, given their ease of maintenance.

Whilst a great staple for the indoor aquarium, Guppies can live quite happily in an outdoor pond, providing provision is made for temperature control. A heater would be uneconomical, although it is an option, so if you don’t live in a suitable stable climate your Guppies would need to be brought indoors during the harsher winter months.

Provision too must be made to provide shade, see our article on how much sunlight ponds need for more info, and netting placed across the pond to prevent your Guppies jumping from the pool, and will also trap organic matter, such as falling leaves, from accumulating at the bottom of your pond.

Being prolific breeders and the bearers of live fry, you will soon find that your stock increases providing an added interest – keep an eye on the numbers though, although overcrowding tends to be less of a problem in an outdoor pond.

Enjoying mosquito larvae, they’ll help keep your mosquito’s at bay during the summer if you elect for an outside pond.

All round, Guppies are an active, colorful and easy going tropical fish that will happily coexist with many other species of fish within either the aquarium or outdoor pool environment.

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