
Having a wildlife pond in your garden or polytunnel is one of the most beneficial things you can do. A pond attracts a range of wildlife, provides habitats and breeding grounds, promotes relaxation, provides education and looks great! However, adding UK pond fish can take your wildlife pond further. Keeping and caring for fish has proven to be a fantastic stress-reliever, and these low-maintenance animals will bring your wildlife pond to life. So, to help you choose your next pond addition, here are six of the best UK pond fish you need in your pond.
Goldfish
Goldfish are the most popular UK pond fish in gardens across the country and one of the most recognisable, particularly the common species. The common goldfish lives up to its name with scales that shine a gold-orange or yellow colour with a single, short tail. The average common goldfish will grow to around 10 inches long[i].
Goldfish are a pretty hardy species that will adapt quickly. Also, they will happily feast on live bugs and larvae that live on the surface of their pond water and aren’t large waste producers. Due to this, goldfish are a fantastic, low-maintenance species for beginner fish keepers.
Carp
Surprisingly, carp are not native British pond fish. They originated in the Caspian Sea but were introduced to our waters by monks a long time ago. Now, you can find them in most bodies of water around the UK. The common carp is the most popular type of carp for UK ponds and the most representative of the original species. However, a common carp can grow up to 5 feet long, so it is unsuitable for small ponds[ii].
The common carp has small scales that range from grey to bronze in colour, small eyes on the top of the head and an elongated dorsal fin. Although it is tolerant of many conditions, common carp prefer large bodies of slow water. Additionally, the omnivorous common carp will feed upon aquatic plants and insects. Although you may have heard that they eat smaller fish, this rarely happens if they run out of other natural food sources.
Finally, although several types of carp will enjoy living in a pond, you should never keep a grass carp in a pond where there is a risk of them escaping. They are an invasive species and may destroy wildlife and fish habitats in the wild.
Koi Carp
Koi carp are ornamental variations of carp, specifically bred for fish keeping. Since koi carp are available in a range of sizes, colours and shapes, they are one of the most popular types of UK pond fish on the market. Although koi carp come in an assortment of colours, the most common colours for koi fish are red, yellow, blue, black and white.
Koi carp are relatively large fish, hitting around 15 inches in length on average[iii]. They are cold-water fish who prefer a pond in partial shade. Although koi carp are hardy fish and relatively low maintenance, they can suffer from several health problems if the water is in poor condition. So, ensure you create a healthy water environment to keep koi carp healthy.
Orfe
Orfe are fast, stream-lined fish, with the most common UK pond fish species being the Golden Orfe. The golden orfe gets its nickname of ‘Carrot’ from its bright orange colour and fanned red fins. Golden orfe are sociable fish that will happily cohabit with many other fish, although they may eat smaller fish if they have no other natural sources. However, you shouldn’t keep orfe alone, as they may die without a group of at least three other orfes.
Orfe are generally considered hardy fish that will adapt well to different environments – they can even survive in extreme water temperatures for short periods of time. However, since they have voracious appetites, you may have to supplement their diet with foods like earthworms and meat-based pellets or flakes.
Sterlet
Sturgeon are a popular species among fish keepers, and the sterlet is a smaller variety perfect for smaller ponds. Unlike many other sturgeons, the sterlet has a slow growth rate and limited full size, reaching only around 1 metre in length[iv]. Similar to a sturgeon in appearance, the sterlet has white-brown scales, white-edged fins and a long, thin snout.
Although a common belief is that sterlets and sturgeons feed by cleaning the bottom of the pond, this is untrue. You must supplement a sterlet’s diet with fish meat or similar animal sources. Plus, you have to ensure that sterlets have good oxygenation, particularly in the summer months. Despite this, sterlets are relatively easy UK pond fish for beginner fish keepers, as they are reasonably low maintenance on the whole.
Pond Snails
Pond snails are an unusual type of aquatic snail that you may not have considered for your pond. However, they are very beneficial to the ecosystem of a pond and eat many kinds of algae and decaying organic matter. There are several species of pond snails; however, the most common is the great pond snail, a large air-breathing species.
Pond snails will happily eat organic matter that is dirtying your pond, although you can supplement their diet with some fresh green leaves. Pond snails can survive in almost any aquatic habitat, including extreme temperatures and smaller water levels. Overall, pond snails are a low-maintenance addition to a wildlife pond and will need little care.
If you do introduce pond snails, you must find a good balance – try not to let populations get out of hand as they can quickly take over your pond. The best way to solve an escalating population of pond snails is simply removing the excess individuals by hand.
Building A Pond In Your Polytunnel

Creating a water garden in your polytunnel brings many benefits, not limited to the range of exotic fish it allows you to keep and care for. By building a simple pond in your polytunnel, you can:
- Attract a diverse range of beneficial wildlife
- Regulate the temperature of your polytunnel
- Grow aquatic plants
- Create an enhanced food growing system
- Make a more pleasant recreational space
Fortunately, you can make a wildlife pond in your polytunnel from just about anything! Of course, a large, in-ground pond will reap the most benefits; however, if you don’t have the room or money to spare for such a significant investment, you could build a container pond. A container pond is a small body of water kept within a container of your choice, and it allows you to grow a number of aquatic plants and look after a range of the UK pond fish we’ve discussed so far.
To make a container pond for your polytunnel, all you’ll need is:
- A recycled watertight container
- Gravel
- Old rocks and pebbles
- Pond plants
Here is how to make a container pond in your polytunnel:
- Choose where you want your container pond to go. It needs some sun but not full sunlight, so try and place it somewhere in your polytunnel where it will have a bit of protection. Also, make sure wildlife have access to your pond. You could dig it into the ground or create small ladders from stones to allow this.
- Once you’ve placed your container in the right spot, line it with gravel. If your container isn’t completely watertight, you can first line it with pond liner.
- Next, fill your pond. Ideally, you should use rainwater for this, as tap water contains harmful chemicals. However, you can fill your container with tap water and then leave it for 24 hours to let the chemicals evaporate before continuing.
- Finally, add your pond plants. You don’t need many aquatic plants – one or two will do, but make sure they are native. Once your plants are installed, you can sit back and wait to see what visitors your wildlife pond receives!
Take a look at our staging options to help you support a pond in your polytunnel.
That is how to make a simple container pond for your polytunnel! If you are planning to keep types of pond fish in your container pond, you will be more than able to do so. First, however, you will need a form of pond filtration – you can read more on that here.
Once you have set up your pond filter, you can keep a range of small pond fish in your polytunnel. Some of our favourite small pond fish for your polytunnel container pond are:
- Golden rudd
- Sterlet
- Goldfish
- Mosquito fish
Choosing Your UK Pond Fish
There is plenty of UK pond fish for you to choose from for your wildlife pond. Whether you’re a beginner fish keeper looking for low-maintenance types of pond fish or an experienced aquarist attempting to expand your pond, we’re sure some of our native British pond fish will suit your needs.
What do you think are the best pond fish? Leave your recommendations in the comments.
Source
[i] https://www.fishkeeping.co.uk/articles_74/goldfish-size-life-expectancy.htm
[ii] https://www.pondlife.me.uk/koi/common.php
[iii] https://www.koiacres.com/koi/faq.html
[iv] http://www.sturgeon-web.co.uk/sterlet-sturgeon-acipenser-ruthenus
Sean Barker is the MD of First Tunnels, and is enthusiastic about providing quality gardening supplies to gardeners across the UK