Pond Building Guide

As we finally begin to see the return of warmer weather in the UK, many homeowners will be turning their attention to their garden - tidying it up from the winter season in time for the summer. Whilst having a well-maintained garden gives us a place to relax and enjoy the sunshine during summer months, adding a pond adds peace and tranquillity whilst allowing the wildlife in your garden to thrive. 

If you don't have any experience of building a pond, it can seem quite a daunting task - especially for DIY beginners. However, by following some of the tips and tricks that Pond Planet have learned over the past 50 years in the pond industry, you'll be able to plan and build your very own garden pond. 

Let's build:

Pond Construction

1. Outline Pond Shape

Before you go ahead and start digging out your pond, we'd recommend you lay out the shape of your pond first using rope. This allows you to iron out any issues you may run into, get the shape correct and get a feeling of how much space the pond will take up in your garden - without starting to dig and commit to a location or shape. 

When choosing a location for your pond, it's best to keep it away from overhanging trees and heavy foliage. This will make maintaining the pond easier in the future, as it's less likely rogue leaves and debris will make their way into your pond. Many online guides will recommend you position your pond where it'll get plenty of sunlight, but this isn't 100% necessary. Whilst some pond plants and animals prefer sunlight, there's an equal amount that prefers shady areas - so don't worry about this too much. Plus, if your pond receives too much sunlight, this creates the perfect conditions for excessive algae growth - which you don't want. 

2. Begin Digging

Once you're happy with the shape and position of the soon-to-be pond that you marked out with rope, you can begin digging. There's no going back once you begin this step (without having to patch your grass up) so make sure the positioning is correct. Begin digging around the outer edge and work inwards - making sure you create sloping sides rather than vertical. 

We've included digging tips below, and you should dig your pond with a slope of 1:10 to allow for debris to be pushed down towards the pump at the deep end. Remember, the depth of your pond will have an effect on pond volume, so make sure this is suitable for what your pump can handle. 

3. Add Plant Shelves

Now you have the basic shape, you can begin creating your plant shelves; where your plants will sit once the pond is filled with water. You can dig planting shelves around the whole parameter, except from the point of water return - as they'll disrupt the water flow and debris from the plants will be pushed into the pond. 

The planting shelves should be big enough to allow a pond basket to sit comfortably without the risk of falling deeper into the pond, whilst allowing the top of the basket to sit approximately 2-3cm below the water surface. 

Pond Planet's Top Tips:

Digging Your Pond

We would recommend building your pond with a slope of 1:10. Try to dig your pond with a rounded shape without dead spots such as L-shapes unless this is critical to the design.

Advantages:

- Good circulation
- Debris is pushed towards the pump and then removed by the filter.
- Deeper area created shelter and protection during the winter and from predators such as herons.
- Allows high surface area with control over volume which can be crucial for filtration. Simply increase the slope to decrease pond volume and vice versa.

Planting Shelves

- Planting shelves can be installed all around the pond except at the point of the water return.
- Shelves should be wide and deep enough to support the chosen size pond basket.
- The top of the basket should be 2-3cm below the water level.

Hiding Pond Liner

Banish unsightly pond liner to improve the appearance of your pond with this top tip.

Simply include a 5 to 10cm deep ledge around your pond suitable for your chosen stonework.

4. Install Pond Underlay

Once you're happy with the overall shape of your pond and you've added plant shelves where you wanted, you can begin to get your pond ready for filling. But first, you should lay your pond underlay and liner. Begin by making sure there are no sharp objects, such as stones, present where your pond underlay will be installed - discarding of any found - as this increases the risk of your pond liner failing when installed. 

Whilst pond underlay isn't always necessary, especially in areas of the pond which experience little weight (such as the sides), it will prolong the life of the liner in most cases. If your excavation area is particularly rough, you can add a layer of sand below the pond underlay. As a general rule of thumb, we recommend you purchase the same amount of underlay as you do pond liner. 

5. Install Pond Liner

Next up is the pond liner. Once you're certain you've covered all areas that may pose a risk to the pond liner, you can begin laying over the top of the excavation. Ensure that the liner is laid evenly over the excavation hole and any creases are folded over neatly to prevent creating areas of weakness; which may cause the liner to fail in the future. If you need to get into the hold to lay the liner correctly, make sure you take off your shoes to minimise the risk of damaging the liner. You can add a small amount of water here to weigh the liner down whilst you position it corrects and get rid of creases; making sure you leave at least a 50cm overlap around the sides. 

Pond Liner Calculator

6. Fill Pond With Water

Once the pond liner is laid out correctly and you have neatened up any creases and ensured there's adequate overhang (50cm+), you can begin to fill the pond. This should be done slowly as the liner can move slightly as the weight of the water pushes it down into any spaces, so make sure you keep a close eye on all folds and pull and tuck the liner where there are any areas which could place additional stress on the liner to leave a neat finish.

Once filled completely, you should ideally leave the pond overnight to allow it to settle adequately. Lastly, you should trim off any excess around the edges; making sure you maintain a 30cm overlap around the full parameter. You can then add rocks around the parameter of the pond for decoration and help hide any unsightly pond liner - this will also help secure the liner in place. 

Adding Pond Equipment

Once you've added the rocks to provide that finished look to your pond, you can begin to add the equipment that's responsible for maintaining your water quality and allowing your pond to be habitable. There are a few decisions to make here, but you'd have already addressed these in the planning stages before starting to build your pond: 

Every pond needs a pump that's capable of providing sufficient flow rate; so your pond is fed filtered water at a recommended rate. Before you choose a pump, you should calculate your required flow rate. As a rough guide, we'd recommend that your maximum flow rate is at least half of your pond volume. This is because it's recommended that water is circulated around your pond at least every 2 hours to help maintain optimal water conditions. As an example, if you have a 4000-litre pond, you should look at pumps that have a maximum flow rate of at least 2000 litres per hour. The maximum flow rate of every pump that we sell is clearly illustrated in each product description; making it easy to find the ideal pump for your pond.  

As for your filter, you have a couple of choices here. We've noted down the main advantages and disadvantages of each below, but there's a fundamental difference between the two that will decide how you construct your pond. If you head down the box filter route, you'll need to make sure the box filter is positioned in an elevated position above the pond - on a hill or platform - as these systems aren't pressurised so rely on gravity to feed the water back into the pond. You'll also need to think about how you can disguise the filter box, as these can be quite large and distract from the natural look you're trying to achieve with a pond. Here, you can opt for a small fence or hide the box with foliage - you can get creative here. If you opt for a pressurised filter, the main advantages are they can be buried 80% below the ground (with filter rock covers available to hide them completely) and don't need to be installed in an elevated position. However, there are pro's and con's to each system. 

In terms of filtration capacity, this is something that should be considered when looking for an appropriate filter. Again, the maximum pond volume the filter can handle is clearly stated in each filter product description. Here, it's important your pond pumps flow rate doesn't exceed the pond filters maximum output capacity, as this will pass water through the filter too quickly and it won't be cleaned/ filtered properly. To make things easier, we've put together a collection of pump and filter kits for you to choose from - ensuring the pump and filter are compatible with each other.

Filtration Types

Pressure Filter

 

PROSCONS
Easy to hide (80% buried)More expensive to purchase
Rock covers availableLarger pump required
Pipework can be where requiredSmaller maximum filtration capacity
Can be sighted anywhere in pipework run
Most have backwash cleaning systems

Box Filter

 

PROSCONS
Cheaper to purchaseHarder to hide
Larger maximum filtration capacityReturn pipework must flow downhill
Cheaper to run as pump doesn’t have to be as largeGenerally harder to clean than pressure systems

Finished Pond

Pond Building Essentials:

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