How to buy or build the best garden pond - Which?

2022-09-03 10:40:59 By : Ms. MIRA XIA

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Whether you're looking for a fish pond, a waterfall feature or simply a place for plants to inhabit, a garden pond provides a focal point that can really transform your outdoor space.  

But choosing the type of garden pond you want is only the first step. You also need to think about whether you want to build your own pond or buy it ready-made, how much to spend on it and how to maintain it. 

Keep scrolling for tons of garden pond ideas, estimated costs for different designs and the best pond plants to consider. 

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If you live in an area with a hosepipe ban you won't be able to use your hose to fill a new pond. If you already have a pond, you're also banned from topping it up, unless you have a fish pond that needs to be filled to safeguard the fishes welfare. 

Make sure you've got the right tools for the job. We round up the best spades , reveal the top gardening gloves  and run through how to buy the best wheelbarrow . 

We've listed the pros and cons of some of the most popular pond types, along with design ideas and maintenance tips. 

Small ponds are great if you're on a budget because they can be made from any reasonably sized container; large flower pots, washing-up bowls or even unwanted farmhouse sinks all have potential.

The concept is the same as a traditional garden pond, it's just smaller. You can either dig a hole for your container to sit in, so the water is at the same level as the surrounding area, or have it sitting on top of the ground. You will need to add gravel and rocks to create an underwater environment and one or two pond plants.

In the autumn you may need to remove fallen leaves and any invasive plants. 

If you don't fancy digging up the garden but still want to experience the benefits of a water feature, a raised pond is a good solution.

They can be installed on any flat surface and if you buy ready-made they can be quick and easy to assemble. Prices for a raised pond start at just £200 for the most basic design and go up to well over £1,000.

Fish ponds, such as a koi pond, take a bit more work to set up and maintain than other ponds, but can be a beautiful addition to your garden. 

To make sure your fish stay healthy, you'll need to buy a suitably sized pump and a filter system. The pump will keep the water oxygenated, and the filter will ensure the water doesn't become toxic. 

You'll also need to plan the environment the fish will be living in and make sure the pond is deep enough, so it might be easier to get professional help. 

If your pond is more about aesthetics and relaxation than attracting local wildlife. you may want to consider a waterfall pond. 

Whether you feel confident enough to install this type of pond yourself or you need expert help is down to the site, the design and your abilities. However, if you already have an existing pond and are looking to add a waterfall then buying a preformed cascade could be the easiest option. 

A wildlife pond will attract birds, insects, amphibians and mammals and shouldn't be too tricky to set up. 

You want to ensure that you have water of various depths and shallow sloping sides or ledges so animals can get in and out. You should add some pond plants to help oxygenate the water and provide sheltered areas around the pond so the wildlife that visit feel safe. 

You can buy preformed wildlife ponds if you prefer, but you should let the pond become as naturally integrated with the environment in your garden as possible. This also means that your pond won't need a lot of maintenance. 

A plant pond is a perfect option for avid gardeners and plant enthusiasts. It's all about creating an environment where vegetation can flourish, but you should expect some animal species to follow too.

Aim to keep the pond two thirds full of plant life to keep it balanced. This means you’ll only see into one third of your pond's water, but at least the plants will keep the water clear.

We've listed some of the best pond plants further down the page. 

Water fountains are a wonderful source of relaxation and they look great too.

It may be that you chose to build a fountain pond from scratch or you can adapt your current pond by installing a fountain feature instead. 

Fountains are also an effective way of oxygenating your fish pond by constantly breaking the surface of the water. 

Looking for new ways to relax in your garden? Read our guide on how to buy the best hot tub . 

The main difference between buying a rigid ready-made pond (also known as pre-moulded or pre-formed) and using a flexible pond liner is the amount of control you have in choosing the design. 

Pre-moulded ponds are typically made from HDPE (high-density polyethylene) or fibreglass and come in a wide variety of shapes and sizes. It can be placed directly into a hole in your garden and some have ledges where plants can sit or caves where fish can hide away. 

However, if you build your own using a synthetic rubber pond liner you can choose the exact shape, size and design but it will require a bit more physical work. 

Whatever pond you decide on, make sure you can enjoy it when the sun goes down by picking up one of our best solar garden light sets . 

Generally speaking, a pond should be at at least 60cm (2ft) deep if you want to care for plants and fish. If the water isn't deep enough, it can freeze in lower temperatures and evaporate in the heat of summer. 

However, if you're installing a pond for koi carp then it should be at least 90cm (3ft) deep.

If your garden pond needs large excavation machinery or it might affect important wildlife/archaeological sites or drainage systems, you may need planning permission before building.

But in most cases if you own the land you should be fine to go ahead without it. We recommend giving your local planning authority a call beforehand to check and get a response in writing.  

Best lawnmowers - tidy up the lawn before tackling your new pond build. 

The cost of your garden pond will depend on the size, what's going in it and whether you build it yourself or pay a tradesperson instead. 

Basic preformed ponds can cost as little as £30, while more sophisticated or larger options sell for more than £1,000. 

If you plan to build your pond using a liner then depending on the dimensions and shape of your pond, you should expect to pay around £30 for a three meter roll of butyl rubber. 

We also spoke with one of our Trusted Traders and they advised that the starting price for installing a small pond would be around £1,000. 

If you wanted to add a water feature, you would need to pay a further £200 for a pond pump with water outlet, a filtration system and a UV light. 

The complexity of the water feature would influence the price though. For example, a blade fountain or waterfall stream would be lot more expensive than just using the fountain attachment that the pond pump comes with. 

You might also need to factor in the cost of installing an IP-rated mains electricity supply to run certain features. This alone can cost hundreds of pounds. 

If you're looking for a reliable trader in your local area, visit Which? Trusted Traders . 

You'll typically find ready-made ponds in local aquatic and independent garden centres, however there are a few larger online retailers that also stock preformed ponds and accessories. 

Wherever you shop, make sure you pay attention to the returns policy and check for warranties.  

For more details on shopping online safely and arranging refunds for faulty equipment, see our online shopping advice .

The main two types of filtration systems are biological and mechanical. 

A mechanical filtration system works by drawing the pond water through filters made from foam, coarse sand, gravel or filter granules to capture particles of uneaten fish food, fish waste and decayed plant materials. 

In contrast, biological filtration turns the waste in the pond into harmless material using helpful bacteria that build up on the the filtration system. The helpful bacteria can take up to six weeks to form, so it's not the best option if you need to start cleaning your pond immediately. 

Not all ponds need filters though, especially if you're building a wildlife pond with a wide range of plants. Generally, you only need a filter if you have a lots of fish that will be producing large amounts of waste that could be harmful to other pond life. 

Plants are a vital part of creating a bountiful ecosystem in your pond but it's important to select the right ones. 

Aquatic plants can be divided into four groups. They each sit at different levels in and around the water and perform different roles: 

Marginal plants for small ponds include Acorus gramineus ‘Ogon’ (golden variegated sweet flag), Allium schoenoprasum (chives), Caltha palustris ‘Flore Pleno’ (double marsh marigold) and Carex elata ‘Aurea’ (Bowles’  golden sedge).

Oxygenating plants for small ponds include Ceratophyllum demersum (hornwort), Fontinalis antipyretica (willowmoss), Hottonia palustris (waterviolet) and Ranunculus aquatilis (common water crowfoot).

Deep water aquatics include water lilies, Aponogeton distachyos (water hawthorn) and Nuphar lutea (brandy bottle). 

Floating plants include Hydrocharis morsus-ranae (frogbit) and Stratiotes aloides (watersoldier).

See all our best plant recommendations  along with expert advice on how to grow them.

To figure out how many fish can safely live in your pond, you need first need to calculate the size of your pond and how much water it holds. To do this, multiply the pond’s average length with the average width and average depth.

You can either do this in metres or feet, however to convert this into gallons you will need multiply the cubic feet measurement by 6.23.

Advice differs on how many fish you can keep keep in your pond as it really does depend on the species of fish you own and how big they grow. 

As a general guide though, if you are keeping koi, you should allocate 35 gallons per inch of fish. If you are keeping goldfish this should be 20 gallons per inch. This means if your pond has a capacity of 2,000 gallons, you can hold 57 inches of koi fish (5 domestic koi fish) and 100 inches of goldfish (25 common goldfish).

The key is to not overpopulate the water, and remember that fish grow, so keep this in mind when introducing new ones to your pond

Discover which plants and accessories are best for various types of animal using our guides on gardening for wildlife . 

Turning off your pond pump in the winter is normally only necessary in countries with much colder climates. 

In the UK, temperatures don't often drop low enough for there to be any issues. In fact, by keeping the pump on it will ensure the water remains cleaner and a healthier environment for creatures over the winter months. 

If you have a fish or koi pond, Watergarden.co.uk recommends lifting the pump around 30cm (1ft) from the bottom of the pond so that the lower section remains slightly warmer than the surface water.

Best garden kneelers  - avoid cold knees when you're attending to your pond in the winter.