There are over 20 000 different species of algae of which Blanket weed is one type.With so many species it can be quite a challenge to differentiate between them. Blanket weed, however is the most common type found in garden ponds and is easily identified by its long filamentous threads. It has the potential to grow more than 2 meters in a day. With such a rapid growth rate, if not treated quickly enough it has the potential to cover your pond and block the filtration system. Prevention is certainly better than having to deal with the potentially fatal consequences of blanket weed by depriving fish and other aquatic inhabitants of oxygen.

Why is blanket weed common to garden ponds?

Blanket weed is a thread-like, filamentous algae that floats on the water. It forms a dense hair-like green mat attaching itself to rocks or to the side of the pond. If it attaches itself to oxygenating plants the algae will smother the plants preventing them from releasing oxygen into the water.

Blanket weed thrives on sunlight and nutrients in the water. The higher the levels of organic matter the greater the chances of having to deal with this green filamentous algae.

1. Pond over populated with fish – this will lead high levels fish faeces increasing the organic nutrients levels in the water
2. Incorrect pond pump and filter capacity for pond size
3. Dead leaves and plant matter falling into the pond and left to turn to nutrient-rich sludge at the bottom of the pond
4. Pond exposed to fully daily sun light
5. Fertilizer leached into the pond via rainwater run-off from surrounding landscape

Any one of these five will increase the nutrient content in your pond. Blanket weed thrives on nutrients so it you want to reduce the risk of blanket weed then avoid nutrients entering the water.

How to reduce the risk of blanket weed

• Remove plant debris before it sinks to the bottom (particularly during the autumn months) by securing a net over your pond to catch the leaves or regularly skimming-off fallen debris
• Avoid the use of fertilizers on your lawn
• Top-up pond water levels with rainwater rather than tap water as the former is believed to have less nutrients such as calcium
• Pot plants in low nutrient aquatic soil only
• Add water lilies to your pond. They add shade and protection for fish and other aquatic inhabitants. They also use-up nutrients leaving little for blanket weed to thrive off
• Avoid over feeding fish. Uneaten food will turn to sludge and increase water nutrient levels
• Remove sludge from the bottom of your pond – the result of decaying plants, fallen leaves and fish waste left to rot. This can be done by vacuuming the bottom of your pond

There are various treatments available from aquatic stores to treat blanket weed. For garden ponds home to gold fish or aquatic plants only then the introduction of pond snails is a wise choice. Snails will eat pond algae such as blanket weed, uneaten fish food and decaying matter. They are recognised as an ecologically safe way to control algae without the use of chemicals. For Koi ponds, use barley straw logs to rid your pond of algae.

The positive effects of blanket weed

While high levels of blanket weed can be disastrous to your pond, in small concentrations they actually have the ability to cleanse and purify the water by using up organic nutrients present in the water. A pond completely free of algae may not be possible but keeping the nutrient levels low by following the above mentioned 7 points will go along way to a happy, healthy and well balanced pond.

Heron are notorious for searching out fish ponds for easy pickings during the nesting season. Not only do they have the determination to deplete an entire fish stock from a pond but there is also the potential risk of them damaging the pond liner.

Observing these birds habits and actions has helped to find ways of preventing them from feeding on the fish in garden ponds. Heron are tall (90-100cm), with a long neck, long legs to allow them to wade in water and a dagger-like beak evolved for snapping up fish. When in search of food it stands completely motionless in the water, waiting for a fish to swim close enough for it to swiftly seize it.

The grey heron wades into water and fishes in the water from a standing position. There are various products available from aquatic stockists or you can make your own ‘Heron proofing’.

• Netting – Persuading herons not to raid fish ponds is very difficult. Netting is considered by many fish pond owners to be the only effective protection. The downside, however is that marginal plants are likely to get caught-up in the netting. A sheet of black mesh pulled taut above the water is also a good option because plants can grow through. Mesh secured at a height of about 30cm above the water will still allow small birds to access the pond from the edges.
• Stakes – If netting detracts from the beauty of your pond or gets in the way when cutting back plants etc, then another option is to dig wooden posts into the ground around the periphery. Attach a length of rope to each of the posts to stop herons wading into your pond. This method has been tested by pond owners with positive outcomes.
• Suspended line – Less glamorous than rope but also less intrusive is the use of fishing gut attached to and held in place by cane, plastic or metal supports at a height 15 to 30cm’s above the ground. This will disturb herons when they walk towards the pond where there isn’t ample shallow beached areas to allow them to land straight into the water.
• Shelter – Floating plants such as the waterlily offer shelter from predators as do overhanging boulders.
• Vertical sided ponds – Herons prefer to fish in shallow water, so vertically sided ponds with depths of 1.2 meters or more are less attractive. Fish in steep-sided ponds are therefore less likely to get frightened off unless one at the surface is stabbed by a heron swooping over the pond.
• Dog – Pets left to run around freely in the garden can make it a less attractive place for heron to visit.

While these protective measures offer some resistance to unwanted heron visits, pond fish are only really safe when they hide at the bottom depths of a pond.

Herons are a protected species so for that reason plus the fact that past winters have been relatively mild has resulted in an increase in heron numbers in the UK. You are likely to see them roosting in rural treetops particularly near rivers and canals. They can, however travel great distances in search of food so visits to urban ponds are not uncommon. An adult heron needs up to half a kilogram of food per day, so can be extremely persistent and determined in their hunt for food which is why fully protecting a fish pond can be such a huge challenge. In spring and early winter fish are sluggish coming out of or going into a period of dormancy, so become easy targets. This really is a time you need to be most vigilant against these unwanted visitors.

It is well documented that a garden pond will add an element of peace and tranquility to any outdoor space.  Whether a wildlife pond or one that is home to fish, they are also a source of water that will attract an abundance of creatures without much effort.

We have been called to rescue garden ponds loosing water so we do strongly suggest the use of an underlay and pond liner for all pond builds. Flexible pond liners such as Epalyn and Butyl are the most commonly used, as they will adapt to any size and shape. PVC pond liners are relatively cheap, but they deteriorate when exposed to sunlight, puncture more readily and are short-lived. Butyl and Epalyn rubber are more expensive, but durable and will last 30-50 years.

In this article we offer advice on how to line and edge a wildlife garden pond with a rubber pond liner while still being able to maintain an informal look. The role of a pond liner is to prevent the lose of water while also helping to maintain a healthy pond ecosystem.

Designing your wildlife pond

• Make your pond as big as possible to create many and varied habitats. The Wildlife Trust suggests a pond 1m wide by 2m long to be an ideal size.
• The deepest part should be at least 0.5 to 0.8 meters. A pond that is too shallow will heat-up too quickly in summer with the risk of turning green and ice over in winter starving your pond of oxygen.
• Ensure some edges are shallow and sloping to allow amphibians and small creatures easy access and exit.
• Include planting shelves. Place boulders intermittently between baskets planted up with plants, merging with the rim of the pond for a natural progression from land into water while also secure the pond liner in place. Aquatic plants provide much needed shelter and protection from predators. This creative mix of plant and boulders meeting with the edge of the pond also hides the visibility of the pond liner.
• Add native plants from other garden ponds or garden centres. Never take plants from the wild. March is a great time to construct a pond and add plants giving them all season to establish themselves.
• Include a rim or lip around your pond particularly if you intend using turf for the edging. The lip is there to prevent water and soil from draining from the cut turf into the pond bringing with it unwanted nutrients.

This photo is a of a very big and deep pond in construction. I have shared it as an example of a lip or rim to the edge of a pond and to show the underlay overlay on top of which the pond liner is installed and then edging material or turf is placed to keep both in place.

Pond liner installation

• Remove as many stones, roots and sharp debris from the bottom of the pond to avoid puncturing the pond liner
• First install a protective underlay to protect pond liner from puncturing
• A rubber pond liner such as Butyl or Epalyn is durable, resistant to adverse weather conditions and UV rays. They are both flexible and readily mould into the contours of a pond therefore our preferred choice
• For the beached area of a wildlife pond we also recommend adding an underlay above the pond liner for added protection when adding sand and gravel. The underlay will also help to stop the material used to create the sloping area from sliding into the deepest area of the pond.

Add a turf, boulders or stone slabs to edge a pond

With wildlife ponds there is a variety of methods used in the edging. In many cases all options are used – buried edge, boulders, stone slabs, turf, planted or gravel edges are all used. A buried edge is when the lip of the pond liner is buried in the sand. The only possible negative feature of this type of edging is that when the water level drops the liner is exposed and takes away the ‘natural-look’ of a wildlife pond so it isn’t one of our favoured choices.

When measuring up your pond liner include an extra 10% for the overlay to secure it in place. You can add the underlay both underneath and on top of the pond liner to help the sand or gravel to stick to it in a gradually sloping shallow beached area of a pond. Or, you can glue the boulders to the pond liner with a waterproof sealant. Then lay sod around the pond.

Edging a pond with paving slabs or boulders is a lot easier than using turf, however turf does offer a far more natural transition from land to water. Unlike stone, turf won’t get hot to the touch so is far kinder to small creatures when visiting your pond. If you prefer to edge your wildlife pond with turf, we recommend growing your own to avoid pesticides leaching into your pond.

Use play sand or well washed gravel to create the beached sloping edge into your pond.

Turf growing close to a pond will maintain relatively damp conditions for frogs to hide in move they move from pond to dry land. Turf will need to be maintained by hand to avoid the chance of grass clippings ending up in the water when mowing

Old logs offer a great form of cover and protection to wildlife so add a few around your pond. Add water snails to keep your pond water relatively clean.

When you have finished building your pond insects, amphibians and invertebrates will find your pond surprisingly quickly on their own.

Pond liners are an easy way of containing water for wildlife ponds particularly where the ground is porous. The pond liner does not need to detract from the natural look of your pond. Cover it with smooth surfaced pebbles. Don’t skimp on lining your pond – a high quality material will last for years with a reduced chance of puncturing. Any repair work will upset a well balanced pond with an established ecosystem. Rubber pond liners such as Epalyn (EPDM) or Butyl are non-toxic to wildlife and don’t leach chemicals into the water. These pond liners are durable, flexible and resistant to UV rays so will stand up to sunny conditions and the presence of wildlife for more than 30 years.

“Ponds are a lovely addition to any garden and can provide a rich habitat for a range of wildlife. However, without care ponds can soon become an eyesore with overgrown plants, weeds and water that is unhealthy for fish and other wildlife. Occasional cleaning and regular maintenance are required.” as quoted by the Royal Horticultural Society. With that in mind, here are 7 spring pond maintenance steps to get your pond ready for the months of warm summer weather.

A pond that is well maintained during the Autumn are less likely to require a lot of work at the start of Spring versus those where leaves and dead plant matter have been left to sink to the bottom, and aquatic plants haven’t been cut-back ready for the next growing season. Just as gardens need regular attention, so too does your pond!

Spring pond maintenance tips

1. Give your pond pump and mechanical filter a good cleaning. If you have a bio-filter, then return it to your pond. For more of pond filters, please refer to the next paragraph, which discusses the two filter options and seasonal maintenance requirements.
2. Remove leaves or other debris that may have sunk to the bottom of your pond – as the water warms up, any debris left in your pond will start to decompose and affect the health of fish.
3. Check your fish for any illnesses or wounds.
4. Divide and repot pond plants. Avoid re-potting with soil full of organic matter. Most water plants grow well in sand and don’t require fertiliser. Water lilies are, however, an exception and do require fertiliser for a healthy growth. Water plants get their nutrients from fish waste. If you have extra plants after you have divided them, you may want to consider growing them in low, damp spaces in your garden.
5. For fish ponds, make sure that up to half of the surface of your pond is covered with floating plants as it gives the fish a place to hide from predators and keeps them cool in the heat of the summer. It also keeps the sun from encouraging algae growth.
6. If your pond is lined with a pond liner check that the material you have used for the edging is still in place, sufficiently covering the pond line to prevent any possible damage from claws or the UV rays – rubber pond liners are UV stable and will withstand long periods of UV exposure – but, a bare edging exposing a pond liner can detract from the beauty of the pond.
7. Start feeding your fish small amounts initially but a good guide is to feed enough that will be consumed within 5 minutes

Pond filter options for your garden pond

A mechanical filter works by filtering out dirt, solid waste and algae from the pond water drawn in via a submersible pond pump. Water passes through foam, coarse sand, and filter granules to remove waste matter. This type of filter is inexpensive and usually installed in the pond. It is effective as soon as the system is switched on and can be run intermittently.

A bio-filter or biological filter, works by creating a suitable living environment for certain types of bacteria which ‘clean-up’ the waste material that fish produce – breaking down the waste and recycling it. Fish waste is excreted in the form of ammonia (which is toxic to fish). The naturally occurring bacteria in a pond, known as nitrosomonas breaks down ammonia into nitrite using oxygen to do so. Nitrite is then converted by the bacteria, nitrobacter into nitrate – an important plant food .  An essential spring pond maintenance step for a bio-filter is to return it to the pond and give it a boost of a bacteria/enzyme product to ensure the good bacteria colony starts to grow quickly. Bio-filters efficiency is affected by oxygen supply, temperature and water flow.

If you keep fish then it is advisable to run both a pump and filter (either a bio or mechanical filter) to keep the water clean and simplify pond maintenance. For ponds with aquatic plants only, you should be able to get away with little or no filtration. You can refer to this website for detailed information about the mechanics of pond filters – Pond Filtration Basics

Spring pond maintenance should be seen as a time to step outdoors and relish this amazing time of the year when nature awakens from her winter slumber.

All wildlife from tiny critters to large mammals have the same basic needs namely food, water, shelter (to nest young, provide shade, protection from predators) and living space. Building a pond for wildlife can offer so many creatures these basic needs. There are a number of very valuable reasons why should build a pond to attract wildlife into your garden as discussed here:

Why a wildlife pond for your garden?

1. Garden ponds have an increased importance to wildlife with some 50% of ponds lost to increasing demands on land for houses, agricultural development, commercial buildings and other urban development
2. Important for biodiversity – wildlife ponds support an immense number of plants and animals
3.  Wildlife ponds can make a huge impact on environmental issues that affect us all such as climate change and pollution, as well as being fantastic for wildlife!
4. A source of water to wildlife during dry periods
5. Offers an opportunity to watch and learn about the habits and movements of so many fascinating water-loving creatures
6. Birds love to bathe in shallow waters
7. Plants added around the edges of a pond provide cover for visiting wildlife and a place for frogs to retreat to after the breeding season
8. The great variety of aquatic plants added to a pond assists in maintaining  healthy water quality. Add submerged oxygenators, floating and marginal aquatic plants for a low maintenance pond
9. Provides a most welcome habitat for frogs to breed and spawn. Male frogs will return first to the pond where they were raised and attract the females to them by croaking. Frogs mate in shallow areas of the pond amongst plant growth. The female frog uses plant growth on a shallow shelf area of the pond to support herself during spawning.
10. Ponds attract frogs which in turn control the slug population – and save your vegetable garden and flower-beds!
11. Newt’s natural behaviour is to wander around looking for a pond to colonise. Building a garden pond will help shorten their journey. 
12. A rockery or log-pile built alongside a garden pond will offer a place for newts to hide and shelter at the end of the breeding season.
13. A wildlife pond planted with aquatic plants such as water forget-me-nots, watercress, water speedwell and flote-grass provides a safe place upon which newts can lay their eggs. Newts will lay their eggs in leaves which have become folded over.
14. A pond that has a shallow beached area at one end will provide a bathing area for birds and a source of drinking water for hedgehogs
15. Insects need water to survive too!
16. An invitation for dragonflies and damselflies to visit during the summer months.
17. Keep mosquito numbers down during the summer months by inviting carnivorous damselflies and dragonflies into your garden.
18. Dragonflies and damselflies can only breed in unpolluted water rich in oxygen. They are, therefore a good indicator of the presence of healthy, clean water conditions
19. A pond is likely to attract toads to your garden. They in turn will control insect numbers. Toads thrive on insects and therefore are an alternative to using gardening pesticides to protect your vegetables. Toads are more likely to be attracted into gardens that also offer moist environments under rocks, logs and trees.
20. Attract toads to also eat unwelcome pests such as slugs, snails and mosquitoes
21. Any size pond is important to wildlife. A large pond, however is more likely to attract the presence of waterfowl, including mallard ducks, moorhens and coots
22. Provides a home for rare species like water voles
23. Offers an opportunity to plant aquatic plants for a greater variety of flora in your gardens micro-environment
24. Encourages a greater awareness of caring for our environment. Invest in a rainwater butt so you can top up your pond with clean rainwater which is beneficially lower in nutrients
25. So that wildlife continues to be looked after for future generations
26. Most important feature of an organically maintained garden

Other articles on building a pond for wildlife

How to attract wildlife to your pond

Get funky attracting wildlife to your pond and garden

A flat sheet Epalyn pond liner allows for creative design flexibility and the build of ponds that blend in with the surrounding landscape. The photographs shared here were sent in by one of Liners Online customers. A viewing point has been constructed over the pond offering a marvellous creative feature to compliment the long flowing pond. The decking area offers an idyllic setting to sit, relax and soak-up the beauty of this garden pond build.

Rocks have been used to edge the pond and secure the pond liner in place. If you are planning a similar finish to your pond and are concerned about the rocks bearing down on the pond liner and puncturing it, you can line the top of the pond liner over which the rocks are to be placed, with geotextile protective underlay.

Epalyn pond liners are the ultimate product for UV resistance. The 0.85mm and 1.0mm are the same as 0.75 mm but, give added piece of mind with the extra thickness for more demanding applications. For the average garden pond build the 0.75mm thickness is ideal.

Epalyn offers high flexibility and elongation properties, superior weathering resistance, and due to it’s durability it also offers low maintenance after installation.

Sharing photos of a pond during construction and as a finished product, helps others to draw inspiration from it’s unique qualities. Hence why we are so grateful to able to share photos sent to us by customers.

The transition from summer into autumn is marked by the colour changing of leaves, cooling temperature and the nights getting longer. For the pond owner it is the fall of the leaves that alerts them to the onset of autumn. The lovely hues of  red, orange and brown colours bring an exciting dimension to footpaths, streets and parks. But to ponds there is these fallen leaves risk floating to the bottom of ponds and resulting in dangerous increase in debris levels if not dealt with.

A question that frequently gets asked by pond owners at this time of the year is whether a pond heater is necessary to invest in. If you don’t keep fish in your garden pond then a heater is not needed at all. If you have followed the Autumn Pond Maintenance guidelines as illustrated in the above infographic, then you are not likely to need a heater either and I will explain why.

A pond that ices over for a few days is not likely cause stress to your fish or affect the health of your pond. During the cold winter months fish are less active, their metabolism has slowed and they are eating very little if anything at all. They will also spend the winter at the bottom of the pond where the water is a little warmer. With the slowed metabolism fish excrete less waste into the water. A thorough Autumn pond maintenance regime of cutting back, pruning dead foliage and skimming-off leaves means less organic matter sinks to the bottom of the pond to turn to sludge releasing carbon dioxide into the water as it continues to decay. So, with no sludge and clean healthy water an iced over pond isn’t going to lock in any toxins.

If you live in the northern most parts and you do experience periods of snow and freezing temperatures for extended periods then an aerator or pond heater maybe an option – although leaving a plastic ball floating on the surface of your pond will help prevent it freezing over thereby allowing gases to escape and oxygen to enter the water.

A small picturesque waterfall can add a fascinating dimension to a garden pond of any size. The tranquil sound of water splashing into a pond below will turn the most ordinary of gardens into a dream oasis – a place to relax and reflect. If you feel inspired to transform an area of your back garden into a water feature with water trickling over rocks into a pool below then here are a few tips to get you started. And, to help you budget for your project, I will share advice on measuring the amount of pond liner and protective underlay for your pond plus water fall extension.

The first step to getting started is to decide where you are going to site your garden pond so that it offers maximum visibility from your house. The next important step is deciding what type of pond – to home Koi carp, to display a stunning array or aquatic plants or a pond built for the purpose of attracting wildlife? Koi need as big a surface area as possible and a pond depth of no less than 1.5 meters. A waterfall will aerate the water acting as a natural oxygenator – helps maintain healthy water and reduce algae growth while providing oxygen to both fish and aquatic plants. But, cascading water can also be hazardous to pond inhabitants so  keep this in mind when planning your build.

The best advice given by pond experts and landscape professionals is to do thorough research before embarking on any pond project. This will allow for a confident execution of your pond build as well as save on time and budget. Success is built on the foundation of thorough research! Join pond forum groups to see photos of established ponds. They also provide a platform to bounce off any questions you may have.  Dedicated pond liner suppliers are generally experts and will be able to advice you accordingly too.

Using all the research you have gathered together, you can now start planning the design of your pond and waterfall. Refer to a previous article post, for Tips on designing your garden pond

There are preformed ponds and waterfalls which can be bought from specialist suppliers. A less expensive option which is what we prefer is the use of an underlay and flexible rubber pond liner. The reason – allows design flexibility and looks more natural.

List of equipment to build pond and waterfall

To budget your project and to ensure you have everything at hand when you start your project to avoid delays. Here is a list of equipment to get you started >>

• rubber pond liner
• protective underlay
• high efficiency submersible pond pump (possibly 2 – one for the pond to pump water through a filter and the other to pump water for flow into pond along waterfall)
• filter
• Tubing for pumped water to top of waterfall
• rocks/boulders
• stone slabs – pond edging and for waterfall contouring
• sandpit sand (fine grained) – if your garden is flat use the sand dug out to create your pond to build the contours for waterfall for smooth out with layer of fine grained sand
• hosepipe
• Extra wide repair strip – used to join the the pond liner where it meets at the base of the waterfall
• waterproof adhesive sealant

How to calculate pond liner dimensions?

To budget for your project take the measurements from your planned pond build scaled diagrams as follows:

• Measure the longest length
• Measure the widest width
• Measure the depth from the deepest area of your pond

Add to your calculation an amount needed for the pond liner overlap (0.15m) – this is so you can secure your pond liner in place using your chosen edging material.

How much of an overlay or overlap to add into your calculation really depends on how you plan to fix your pond liner in place. So, increase or decrease the amount of overlay depending on installation and edging method.

The pond liner calculation will look like this:

• Maximum length + (2 x depth) +2 x 0.15m overlap = Total Length of Liner
• Maximum width + (2 x depth) + 2 x 0.15m overlap = Total Width of Liner

For a more detailed discussion on determining pond liner measurements, please refer to a previous blog article, How much pond liner do I need?

Do the same for the proposed area over which water will flow into your pond as a length and width measurement with sufficient width to secure the liner in place using rocks and slabs.

In your pre-planning phase and to get a good feel for what your finished product will look like, you can use boxes of different shapes and sizes balanced on top of each other and side by side – just an idea and also helpful when measuring-up ahead of placing your order.

Building pond and sculpturing waterfall

• mark out the outline of your pond design using rope, hosepipe or spray paint
• start digging reserving the soil to build-up the ground for your waterfall (or stream – if gentle gradient is preferred)
• sculpture the sand to the desired gradient and steps
• trample down on the soil to make compact
• line with protective underlay pressing it into the steps and contours of your earthy mound
• clear the bottom of pond of stones and gravel to prevent damage to liner
• install underlay and pond liner pushing it into all the contours and adding neat pleats for a perfect finish – for more tips, please refer to this article on Pond Build and Pond Liner Installation
• lay rocks and paving blocks onto the waterfall securing them in place. Use waterproof adhesive sealant if necessary
• house the pond pump in an appropriate position to pump water through a tube from pond to waterfall

Landscape the area around your pond and along the waterfall. The final step is the addition of aquatic plants and fish. Then sit back and enjoy the sheer tranquility you have bought to your home and garden – the 4th room will be paradise!

Garden ponds, as all enthusiasts will agree bring so much joy and tranquility to a garden of any size. But, they can also be considered a hazard to young children particularly between the ages of 1 to 5 years old. Pond safety should be an important consideration.  Visiting children are a higher risk as they are not likely to be aware of the potential dangers of water. If you have young grandchildren or entertain families with young children there are steps you can take to ensure their safety around your pond.

Children are easily drawn to water so even having neighbours with young children should be enough to alert you to putting pond safety measures in place. A drowning can happen within minutes of a parent being distracted.

Overgrown ponds are reported to be the most hazardous as the transition from ground to water is far less obvious.

Pond safety tips

• Site your pond where it is visible from the house and from the patio or outdoor seating area
• Consider building a raised pond
• For ground level ponds have a gently sloping edge to allow for an easy way of exiting the water
• Install a fence around your pond. If this is your preferred safety measure the fence will need to be higher than 1.1m with a lockable gate. The lock must be as high up as possible.  The better option would be a gate with a spring attached should the gate accidentally be left unlocked. A gate which opens outwards will make it even more difficult to gain access
• Grow plants around the deeper side of your pond to deter children gaining access. Planting should not block visibility of your pond from view points
• Install an OFSTED approved metal pond guard or cover. Chicken wire won’t hold-up against the weight of a child so is not considered a safety measure and should be avoided at all costs
• Make sure the edging and boulders around your pond are firmly in place to avoid trips, slips and falls. The edging should be clearly defined
• Maintain your pond through the seasons and prune back aquatic plants so that at least a third of the pond surface is exposed to sunlight

The Child Accident Prevention Trust (CAPT) says drowning is one of the five principal causes of serious injuries for the under-fives in England. The charity’s campaigns manager, Pamela Prentice, says: “Most drownings involving two to three-year-olds happen in the home and garden.”

According to government figures, four out of five residential pond drowning incidents do not happen at the child’s own home. So while you may have a perfectly safe water feature, your neighbours, friends and relatives may not.

According to Froglife and many wildlife charities, filling-in ponds rather than putting safety measures in place should always be a last resort, since the damage this can do to wildlife communities locally can be enormous. Ponds are great for teaching children about wildlife and the different stages of the life-cycle of small creatures such as frogs unfold in natural surroundings.

Adults with young children in their care should be vigilant at all times – even a bucket of water is a potential hazard.

As with all home and garden projects careful planning is required. So, in this article I aim to share all the steps you need to put in place including a project budget if you are going to include a pond liner, underlay, pond pump, filter, aquatic plants, fish and other finishing touches to your build.

With any pond build, the first and most important step is to decide what the purpose of your pond will be. Is it to attract wildlife, to keep gold fish, home Koi Carp or grow aquatic plants. Are you going to use natural or a mechanical water quality control system?

• for aquatic planting you will need to add a stepped base or shelf to your design plan.  The shelves can be used to accommodate marginal plants of varying heights or to place planting baskets. Shelves make it easier to remove plants to cut back at the end of the season and for general pond maintenance. The design and planning for this type of pond is much like the steps you would take when planning what to plant in a flower bed so that choice works together in a creative fashion.
• for a fish pond, water volume is an important factor when considering design and size. The bigger the pond, the easier it is to maintain healthy water levels. Goldfish require a pond of at least 5 meter square and a depth of no less than half a meter – or a volume of 3000 litres. Koi require a minimum of 5500 litres – or minimum pond size of 2.5m x 2m x 1.2m. There is also a maximum depth – a Koi pond shouldn’t be deeper than 3 meters because sunlight won’t penetrate sufficiently to promote the vital growth of healthy algae. Koi are big fish and need a large volume of water. They also produce high amounts of waste. For both those reasons, a steep or vertical sided pond is recommended. It guarantees the largest volume of water for the space occupied by the pond and steep sides don’t accumulate waste materials and debris that can release harmful ammonia.
• a wildlife pond is probably the easiest type to build and maintain. No retainer wall or brick work involved. A wildlife pond just needs a sloping edge so small creatures such as frogs can easily enter and get out.
• a natural pond is one in which the water, soil, plants, and animals all live in harmony. There is no man-made intervention such as a pond liner to contain the water or pond pump to aerate the water.

What size pond?

The bigger the pond the easier it will be to maintain relative to a small shallow water feature. This is because a small pond gets warm quicker in summer and is more likely to freeze over in winter relative to a bigger and deeper pond. However, there are solutions to every situation – when the temperatures rise during the summer months add extra aeration to your pond – use an air pump to achieve this and make sure your pond receives sufficient shade.  Use a pond thermometer if you plan on homing fish and keep an eye out for any signs of distress.  The lethal water temperature for Koi and goldfish is reportedly 90 degrees F. The higher the water temperature, the less dissolved oxygen it is capable of holding. Fish have a greater demand for oxygen at higher temperatures so the distress they show is due to breathing difficulties.

Pond location

The next step is to decide where to position your pond. A formal pond into which a box-welded pond liner is fitted can be raised off the ground or dug into the ground. It is about deciding which fits best with your garden size and overall landscape design.

• site a pond on level ground – this will also help avoid rainwater run-off, which could bring with it fertilisers carried into your pond. Added nutrients will have a negative impact on water quality.
• ponds need 50 to 70% of the water to be in shade. This can be achieved by building your pond under a pergola (or building a pergola to go over your pond) or shaded in relation to the position of your pond to a garden wall or house. Include floating plants can also provide the necessary amount of shade ( fish can’t breath if too much of the surface is covered by aquatic plants). Building your pond too close to a tree to provide the necessary amount of shade is possible although you will have to keep on top of skimming off all the fallen leaves before they sink to the bottom.

Pond design

Now that you know what the purpose is for building your garden pond, the size that we best fit in the space you have available and where you are going to position it – the next step is deciding on design. A box welded pond liner doesn’t restrict you to a geometric with variations of square or rectangular layout. It is possible to be more creative with your design and still have your pond lined without creases or folds to the pond liner. The main criteria is that the design needs to include vertical sides.

Use a length of rope to play around with different shapes until you come up with one that will work in your garden and against the backdrop of your surrounding landscape.

Building your pond

A raised pond can be built using bricks, concrete blocks or railway sleepers. Sunken ponds require digging. The soil dug out can be used in flower beds or to landscape your garden. Once you have finished digging and are fully satisfied with the layout and depth you will need to remove as many of the stones and rough gravel as possible so as not to damage your pond liner. Measure the widest width, the longest length and the deepest point of your pond. These dimensions are necessary to calculate how much pond liner and protective underlay you will need to order.

Installing underlay and pond liner 

It is always best to tackle the job with another pair of helping hands. First unfold the protective underlay and line the hole dug for your pond. Then, with great care unravel the pond liner and, with help lift and place over the pond. Allow your pond liner to sink into the deepest area of your pond. Step barefoot into your pond to carefully push your pond liner into the contours. Pleat and fold as neatly as possible into the corners. Don’t be tempted to cut any excess pond liner until the pond liner has ‘settled in’ and you have filled your pond with water.

 The final step is to decide whether you are going to use natural means of aerating and maintaining water quality or mechanical by way of a pump and filter. The role of a pond pump is to keep the water moving and by so doing it add oxygen to it. A filter added to the pump will remove debris. This is particularly important when keeping fish because their faeces, if left in the water increase the nitrate levels. This in turn affects water quality.

Goldfish and Koi excrete waste into the water in the form of ammonia from their gills and nitrate in their faeces.  And, algae grows in ponds where there are high levels light and nutrients. When nutrient levels get high enough, algae takes over the pond and chokes everything else out.  Ponds lined with a pond liner means there is a lack of soil in the bottom therefore few micro-organisms compared to that of a natural pond. There are also fewer surfaces for mico-organisms to attach to. Therefore you have to create an artificial place for the microbes to live. A filtration system can be used to provide a surface for the micro-organisms to live on. Microbes take-up waste animal and plant matter as they float around in the water keeping the water clear of nutrients needed for algae to thrive.

Building a pond in your garden is such a rewarding challenge to take on. The finished product will provide you with endless enjoyment so I hope these steps help you to get to work on your plans.