A step-by-step guide to building a garden pond

A step-by-step guide to building a garden pond

Whether you’re a keen fishkeeper in search of a new project or you’re looking for a fun way to encourage more natural wildlife in your backyard, building your own garden pond is as exciting as it is rewarding. Great for supporting your local biodiversity, homeowners with sufficient space and interest are encouraged to create these aquatic havens to help provide safe environments for tadpoles to spawn, small animals to drink, and insects to visit. Tending to and enjoying the view of your garden pond can also have health benefits for you, giving you the perfect opportunity to spend more time outdoors in the fresh air.

Setting up a garden pond, whether it’s a natural wildlife pond or one you’ll introduce fish into, may not be the easiest landscaping job, but with the right equipment, space and effort, it's something that anyone can do. You don’t need to hire anyone, and you don’t need to be an expert pondkeeper either - everyone can build a garden pond themselves.

If you’re considering taking on this DIY challenge, follow our complete guide to building and setting up your own garden pond. We’ve covered everything from the equipment you’ll need to buy to the steps you’ll need to take to design, build, and fill your new pond, and even answered some of the most frequently asked questions about building your own pond to help get you started.

What you’ll need: pond equipment list

Before you embark on your new pond-building project, you’ll first need to order all the equipment and materials required to complete it. What you’ll need will depend on whether or not you want to create a planted pond for wildlife to enjoy, or if you’ll be adding fish to your pond such as koi or goldfish. Below, we’ve laid our pond equipment lists for both options, along with our recommendations on our most-loved products to point you in the right direction.

What you need for a wildlife pond

  • Garden space: Wildlife ponds can be big or small, and entirely depend on the amount of space you have available. If you’re limited on space in your garden and just want a small pond, your best option may be to invest in a small above-ground pond, such as the Velda Fountain Pond. Alternatively, if you’re dedicated to creating a sunken pond, you can scale it according to the room you have - having any sized pond is better than having no pond at all!
  • Building equipment: For construction, you’ll need a hosepipe or piece of rope to plan the shape, a shovel to dig it out, a spirit level and plank of wood to check the levelling, and scissors to trim your liner. We’d also recommend adding some safety equipment to your list such as gloves and a kneeling mat to keep you comfortable as you build.
  • Pond underlay: Designed to lengthen the lifespan of your pond and reduce the risk of any damage coming to your pond liner, pond underlays sit beneath your liner. We recommend Oase’s Protective Pond Fleece or Simply Pond’s Underlay, both of which defend against damage from sharp rocks, debris and plant root growth (except for that of bamboo), but you can also save money on your budget by using old carpet or newspapers.
  • Pond liner: The base of your project, you’ll need a pond liner which covers the full width, height and depth of your planned pond. Our handy pond liner calculator will help you work out what size you’ll need, then you can find a range of product options from trusted brands in our full Pond Liners collection.
  • Edging materials: Required to hold the pond liner in place, while also helping to blend the pond into the surrounding area in a refined way, you’ll want to add edging materials such as large rocks, potted plants and maybe even a fishing garden gnome or two to your shopping list.
  • Pond substrate: Essential for encouraging good water quality, limiting algae growth, and supporting plants, you should use a suitable pond substrate at the base of your pond. A product like Velda’s Classic Substrate Pond Gravel is perfect for this, with the light and porous structure of the gravel acting as a biological nutrient host for microorganisms to develop.
  • Pond planting supplies: Whether you’re building a wildlife pond or a fish pond, we’d always recommend incorporating some planted elements into your design. Pond plants are good for oxygenating the water and keeping a naturally-balanced ecosystem, and that’s not even mentioning how beautiful they are to look at. For this, you’ll need planting supplies including pond soil and planting baskets.
  • Water: Finally, you’ll need enough water to fill your pond up. We recommend using rainwater for this as it won’t contain the cleaning chemicals that are added to tap water for our safety, so try to collect as much rain as you can in the weeks leading up to your planned pond build. Alternatively, you can use tap water, but you’ll also need to invest in a dechlorinator, such as the TAP Pond Doctor Dechlorinator, to make sure this is safe for wildlife.

What you need for a fish pond

  • Wildlife pond supplies: If you’re looking to build a fish pond in your garden, you’ll need all of the materials we’ve already listed above. This will give you everything you need for construction of the pond itself, then you’ll need to add all the essential life-support equipment required to keep your new fish healthy and happy, which we’ve added below.
  • Pond pump: The purpose of a pond pump is to keep your water circulating regularly, pushing it through your filter to keep it clean and clear. As you’ll need a filtration system for this to be effective, we’d recommend opting for an all-in-one pump solution such as the Blagdon InPond 5-in-1. Containing a built-in pump, UV clarifier, and mechanical and biological filtration system, this submersible unit is available in a range of sizes to suit the needs of your pond.
  • Pond filter: If you don’t opt for an all-in-one pond pump, you’ll need to invest in a separate filtration system to keep the water quality at a level that can sustain your fish. In our collection of Pond Filters, we have everything from pressure filters to surface skimmers to help keep your water clean and suitable for supporting aquatic life.
  • Pond pest deterrent: From hungry herons to curious cats, defending your pond from neighbours intent on fishing is an ongoing battle best fought with pond pest deterrents. In our collection, we have everything from invisible cover nets to defend from birds to decoy ornaments to deter ground-level visitors.
  • Pond water testers: Important for setting up your fish pond, you’ll need to pay close attention to the quality of your water by running some quick and simple tests. In our collection of water test kits, we have manual and automatic options which can be used by beginners to measure the levels of nitrates, pH balance and more, so you can create an environment suitable for your fishy friends.

How to build a garden pond

Once you have decided on a pond size and purchased all your essential building materials, you can move on to the really exciting bit: building your garden pond. The process is simpler than you might think, but we recommend setting aside a full day to do the construction, and recruiting some helpers to complete the job faster.

If you’re ready to take on the task of building your own garden or fish pond, follow the step-by-step guide below. Alternatively, if you’re set on building an above ground pond, rather than a sunken one, you can follow our guide to installing an above-ground pond on our dedicated blog.

1. Collect rainwater for your pond

A key pond supply which can’t be bought, we recommend setting up a rainwater collection system in the days leading up to your pond construction project. Whether you use buckets or a water butt, keeping as much rainwater as you can will allow you to fill your pond with safe water quickly, rather than needing to rely on dechlorinated tap water.

2. Choose where to build your pond

You likely already have an idea of where you’d like your pond to go in your garden, but not every spot that looks good is practical. Before you move any further, we recommend making sure your chosen place passes the following checks:

  • Stay away from overhanging trees: Falling debris from trees, especially leaves in the autumn, can land in your pond. When this organic matter decomposes, it poses a risk to the ammonia levels in your water.
  • Sufficient supply of sunlight: Finding a spot which gets enough sunlight but still some shade during the day can be tricky. You want somewhere which can support the life of your pond plants, but which isn’t too much of a ‘sun trap’, as too much sunlight can affect water temperature and algae growth.
  • Great views for you: Once all the hard work is done and you have a beautiful pond in your garden, you should be able to enjoy its beauty. Whether you look onto it from your windows, or have an outdoor seating area you want it to be visible from, prioritise having good views of your pond when picking a spot.

3. Lay out the shape of your pond

Using some hose pipe or a piece of rope, lay out the rough size and shape of your pond on the ground. You can get creative with the shape, but we would recommend basing it roughly on the pre-cut liner sizes you can easily get ahold of, letting you cut down on wasted materials and money. You should also pay attention to the space around your planned pond, as you’ll need to leave a perimeter with room for any marginal plants and maintenance access.

4. Dig out the pond

Using a shovel, dig out the entire shape of your pond. There are some rules to follow here to ensure your pond will be suitable for any aquatic creatures you may want to add or visitors you may want to welcome. These include:

  • Depth: As a general rule, you should dig out the entire area to at least 12 inches deep, with a deeper (2-3 feet deep) hole in the centre for some of your pond life to hide or hibernate in. If you’re building a wildlife pond and have no intention of stocking it with fish, you don’t need to go as deep as this and can focus on having shallower areas.
  • Sloped sides: A good pond will have different depths and layers to ensure fish and wildlife have their preferred habitats, so make sure to have some shallow areas and a deeper section in the middle. At least one side should also mimic the shape of a gently sloped beach to allow visitors easy entry and exit.
  • Level: to avoid floods or uneven water, you should use your spirit level to make sure your pond shape is level. If your spirit level is too small to sit across the width of the pond, sit it on top of a plank of wood and lay that over the top to test the level.

5. Prepare the ground and lay out your lining

With your pond shape dug-out in slopes and levels, start to clear out the bottom bed of your pond by removing any rocks and roots that might damage your lining. You can then finish preparing the ground by laying out your pond underlay, whether that’s in the form of a layer of sand and some old carpet or newspapers or a proper pond underlay.

Next, you can lay out your main lining by spreading it over the hold and weighing it down with rocks until it matches the shape perfectly. Once in place, cut off the edges of the liner with scissors or a sharp knife, leaving around 12 inches of excess around the edges. Secure your lining by laying your edging decoration over the excess, such as rocks or slabs. You can beautify this by adding potted plants, repurposed turf from digging up space for the pond, or just soil.

6. Add your pond substrate and fill with water

Once your pond base has been dug and liner secured, start to fill up your pond. To do this, you’ll want to start with a suitable pond substrate such as the Classic Substrate Pond Gravel from Velda. With this base assembled, you can then fill up your pond with the water you gathered in step one. If you haven’t been able to collect enough rainwater, you can leave the pond half-full to collect rain itself over the next few days. Alternatively, you can use tap water which has been treated with a dechlorinator. Regardless of which water type you use, you should leave the pond to settle at least overnight before following the last step.

7. Add the finishing touches

Finally, you can start to put the finishing touches on the project to make your new pond look beautiful. Plants are one of the best ways to do this as they have benefits for the local wildlife and any fish you choose to have, as well as simply looking great. We recommend using native pond plants to help support your local biodiversity.

How to build a fish pond

If you want your garden pond to house fish, as well as entertaining natural wildlife visitors, you’ll have an additional few steps to follow on top of those outlined above.

8. Add your fish pond equipment

While wildlife visitors are easy to provide for, keeping fish in a pond means the additional task of making sure the pond water is habitable for your chosen species. This means you’ll also need to add in all of your pond equipment detailed in the ‘what you need’ section above, including a pond pump and filter. How you install these will depend on the type of pump and filter you’ve chosen (such as an in-pond pump or waterfall filter), so make sure you follow the installation instructions in your product booklet.

9. Add your fish!

Finally, and most excitingly, you can add your fish to your new pond. When introducing fish to the pond you need to cycle the filter and acclimatise them first. This means leaving your pond to fully settle for around six weeks so that it has time to go through the nitrogen cycle, making the water safe for habitation. Then, leaving the fish in the bag they came in, float them in the pond for around 15 minutes. You can then open the bag and gradually introduce the cycled pond water into the bag over the next 15 minutes, giving them the chance to adjust to the new water. Finally, you can submerge the bag completely and allow the fish to swim free!

Frequently asked questions about pond building

When is the best time to build a pond?

While there’s no strict time frame for building a pond and you can do it any time of the year, the best time is late winter. This gives the water and plants time to settle before exploding with life and colour in the springtime.

How deep does a pond have to be?

If you’re building a wildlife pond and don’t want to keep fish, a shallow 30cm-deep pond will be more than suitable for sustaining your plants and wild visitors. However, if you want to keep fish in your pond, they need more space to swim and hide. For this, you’ll need some shallow areas, as well as a deeper portion of around 2-3 feet deep in the middle of the pond. This deeper area also keeps fish safe during the winter months when the surface of the pond may freeze over.

Does a pond need a pump?

The answer to this question changes depending on the type of pond you’re looking to build. If you want a wildlife pond, you don’t need to invest in a pond pump. However, clean, well-circulated water is essential for the wellbeing of a fish pond, so you’ll need a pond pump to push the water through a filter if you intend to keep fish.

Do I need planning permission for a pond in my garden?

In most cases you won’t need to worry about applying for planning permission to build a garden pond as these are considered to be ‘permitted development’ and so don’t require any formal permissions. However, if you’re planning a particularly large pond, you should check with your local authority to make sure it’s allowed.

Which is better, a preformed pond or a liner?

While we’ve laid out how to build a garden pond using a pond liner, you can instead buy a preformed pond and use that as the base for your construction. Preformed ponds are typically considered to be an easier installation option as you don’t need to shape and cut liners and all your layered beds and suitable depths are already laid out for you. However, you do lose some creative freedom on the shape and size of your pond. Which option is best for you will depend on your own personal preferences.

Build your own garden pond with Aquacadabra

Whether you want to bring more wildlife to your doorstep or you’re already an avid aquarium fishkeeper and want to try out a new challenge with pond fish, building your own garden pond is easy, fun and exciting. At Aquacadabra, we have all the essential equipment you need to complete your pond construction project, and our friendly experts are always available to share their advice to make sure you don’t put a step wrong. You can also check out our guide to keeping your pond healthy to get guidance on your ongoing care responsibilities for your new aquatic friends.