7 Important steps to avoid blanket weed covering your pond

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 lifted out from a ponds surface

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.

How to keep heron away from garden fish ponds

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.

Gray heron visiting a pond to fish for food

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.


How to edge an informal wildlife pond and secure the pond liner?

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.

Rim built around the edge of pond to protect from rain runoff flowing into pond

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.

Wildlife pond and fish pond edge finishing ideas for lasting effects

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.

7 essential Spring pond maintenance steps to a healthy ecosystem

“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 checklist

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.

This entry was posted on January 10, 2018, in Garden ponds.

26 Reasons why you should definitely build a pond for wildlife

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. Frogs are attracted to ponds built to attract wildlife
  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

“Of all the habitats you can create to help wildlife, a pond is probably the most effective” RSPB
This entry was posted on November 22, 2017, in Garden ponds.

10 Autumn gardening tasks and garden tools to get them done

The temperatures are dropping and the last of the autumn leaves are falling to the ground creating carpets of yellow, orange and browns. Autumn has it’s own special beauty as it draws the growing season to an end ahead of a period of semi-dormancy – a time to relax and plan for spring! Before winter arrives, however there are a few essential tasks that need doing as discussed here. Investing in essential garden tools will help get these jobs done to a high degree of efficiency.

Autumn garden tasks

  1. Tidy the edges to borders of flower beds – trim the grass, dead-head flowering plants (especially roses), remove weeds and cut back dead branches or stems. For those who love a tidy looking garden, the neat edges to flowerbeds and paving will distract from the grass being a little longer than it would be in spring and summer
  2. Plant bulbs for a vibrant display of colour in spring. Plant daffodils between September and October, tulips in November
  3. Give your lawn it’s last mow and spread an autumn fertiliser to add nutrients while also stopping the growth of weeds and moss. This is also a good time to lay new lawn while ground warm but not too wet
  4. Dig compost or well rotted manure into your flowerbeds to keep plant roots warm over winter
  5. Plant or transplant evergreens, shrubs, roses or hedging while the soil is still warm and is moist enough for easy digging. September to November is considered ideal for tree planting because roots can become established before the ground freezes over
  6. Move frost sensitive potted plants and tender perennials indoors or store in a greenhouse, garage or conservatory – it only takes one night of frost to damage more sensitive types of garden plants. If you don’t have a sheltered place to keep vulnerable plants over the winter months, make sure you cover them with garden fleece or bubble wrap to protect from frost and freezing temperatures. Water less to bring on a state of semi dormancy. Digging in an ample amount of compost mulch or leaf mould should protect other more hardy plants which stay outdoors over winter
  7. Clean garden equipment by removing all traces of rust. Store in a dry place to avoid corrosion
  8. Prune back deciduous hedges
  9. Rake-up leaves as often as you can. Leaves left on the lawn will block sunlight reaching the blades of grass, which may result in brown patches and moss growth. Make leaf mould from the fallen leaves. This will make a soil improver or nutrient rich mulch in which to grow seedlings. Leaf mould can be make by creating a separate leaf heap. The fibrous leaf mould retains moisture and enhances soil drainage. A leaf heap can be constructed using chicken wire and log posts allowing air to circulate. A leaf heap should take a year to rot down
  10. Clean and cover or store garden furniture. Leaving it uncovered could encourage a green mould growing on it which then means having to do a tougher cleaning job before using the furniture again when the weather warms

Autumn is also the perfect time of the year to build a garden pond in your garden. Wildlife will love you for this addition to your outdoor space.

Garden tools to help with some gardening tasks

And, with every job having the right garden tools to hand helps get things done more effectively and efficiently. A grumpy gardener who became frustrated with the garden tools in his shed decided to design his own. Today he has his own unique range of garden tools to keep flowerbeds weed free, hedges and roses neatly pruned back, leaves collected for the leaf composter, weeds and moss carpets removed from between paving and the garden kept tidy through the seasons.

  • use a wheelbarrow booster to triple the loading capacity of your barrow to reduce the number of journeys you have to make to your composter or brown bin
  • a cultivator will help you to break-up and aerate the soil before planting, remove stubborn weeds from flowerbeds and between paving
  • a hand fork to cultivate and hoe flower-beds
  • hand trowel or garden spade with depth markers etched into it so you know how far you need to dig when planting bulbs
  • ergonomically designed secateurs with knuckle guard to avoid scratches to the hand when pruning – not all gardeners like wearing gloves!
  • avoid the pain of kneeling to weed and nurture flowerbeds by investing in a good quality garden kneeling pad that is easy to clean and will last a life time

If, like me you love to potter about in your garden, you would probably agree that the easiest way to tackle these jobs is with the correct garden tools and a garden kneeling pad that will take the pressure off your knees while you enjoy the pleasure of transforming green space into a haven for wildlife and a place to relax and flitter away time during the warm days of summer.Garden tools presented is a gift set with 4 essential gardening tools


This is what one customer did with 0.75mm Epalyn pond liner

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.

Epalyn 0.75mm pond liner supplied to customer and this is the pond he created

Epalyn 0.75mm pond liner supplied to customer and this is the pond he created

This entry was posted on November 3, 2017, in Garden ponds.

Autumn pond maintenance tips vital to your ponds health

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.

Autumn garden pond maintenance tips on this infographic

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.

This entry was posted on October 4, 2017, in Garden ponds.

Calculating pond volume of an irregular shape

The availability of flexible flat sheet pond liners allows for design flexibility. Ponds need not be a regular square, rectangular, or a round shape. Flexible Epalyn and Butyl rubber pond liners mould to the contours of ponds, are durable, resistant to the damaging effects of ultra-violet rays and won’t go brittle with age. Ponds with adventurous shapes add charm and fascination to any amount of garden space. To calculate the pond volume of an irregular shape is a little more challenging and less likely to give an absolute accurate surface area measurement relative to regular shaped ponds. In this article we offer a few tips on how to calculate pond surface area and average pond depth to get as accurate a pond volume as possible.

Calculating the volume in gallons or litres is important if you are wanting to stock your pond with fish. It is also necessary to help determine the size pond pump to reach pond water turnover. Having an accurate measurement of pond volume is also important if ever you have the need to add healthy bacteria or algaecide to the water.

Steps to calculating pond volume

To calculate pond volume of a regular shaped pond, you need to measure the length, width and the depth in either meters or in feet. If your pond is an irregular shape the easiest approach is to divide your pond into regular shapes, determine the surface area of each shape and add the sum of each together. If, for instance your pond is kidney shaped, then divide your pond into three basic shapes – two circles and a rectangle. Measure each separately. Add the three totals together and then multiply by the deepest pond depth to determine volume.

Taking measurements is easiest done prior to filling your pond with water.

  • Draw a square or rectangular shape around your pond by knock stacks into the ground and using string to get as a accurate a shape as possible.
  • If a single rectangle doesn’t fit the shape of your pond, then add other shapes to the layout – or a combination thereof
  • Measure the longest length then do the same for width.
  • Using a sheet of graph paper draw out the shape of your pond using these dimensions.
  • From your drawing of an irregular shape divide it into shapes that are easy to calculate surface area – trapezoid is half the width multiplied by the addition of the two lengths, a triangle is half of base x height and a circle is 3.14159 x radius2.

Or, take a length of rope and lay it around the perimeter and calculate surface area as per example:

  • Pond is say 14 meters
  • Divide 14m by 4 = 3.5mIrregular shaped ponds like this one are more difficult to calculate pond volume accurately
  • Multiply 3.5m x 3.5m
  • Equals surface area of 12.25m
  • Multiply that by the deepest depth of 2m
  • Volume of 24.5
  • Multiply by 1000 to get volume in litres.

If pond has been filled with water you can get a depth measurement by wading into your pond with a stick and marking off the depth/s.

Volume is surface area multiplied by the deepest depth – for ponds with out ledges.  For those with planting ledges, again divide your pond into sections as per the different depths. Measure each depth then add them together and divide by the number of measurements taken.

Pond volume for a trapezoid shaped pond

The purpose of calculating pond volume is to make sure you buy the correct size filter to maintain adequately healthy water conditions for the long-term well being of all pond inhabitants. All filters have a guide to the maximum pond size they will cope with. Manufacturers recommend that the entire volume of a pond should be passed through the filter approximately every two or three hours. It is important to also note that for a filter to work efficiently, it must be teamed with a pond pump that supplies it with a sufficiently strong flow of water.

Knowing the size and capacity of your pond also allows you to calculate how may fish and number of plants to add to your pond. If you intend to have a highly stocked fish pond then it is advisable to install a filter to cope with one and a half times the capacity of the water in your pond.

This is how to measure a pond liner for pond with waterfall

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.Waterfall flowing into a pond

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!

This entry was posted on August 23, 2017, in Garden ponds.

8 important garden pond safety tips

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.

Pond safety measure with a life belt for ponds too deep to wade into

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.


How much pond liner do I need?

Knowing how much pond liner you need will save your budget (and time!) – too big or too small is wasted money. Calculating how much pond liner you need is dependent on the accurate measurements you take of your pond. You will need these to add into a pond liner calculator which will take your measurements to determine the amount of pond liner and protective underlay you will need to order. So, let me take you through how to calculating how much pond liner you need.

Pond liners offer greater flexibility in pond design allowing you carte blanche in creativity. However, the further you move away from the traditional rectangular or circular pond shape the more you need to understand how to take measurements. With all measurements remember to add in a little extra for an overlay (visit ‘Pond planning and construction‘ for more information).

How to take measurements of your pond Pond with wooden bridge going across and bordered by ferns

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

Now, add one side (Length or Width) to two times the depth plus amount needed for the overlap (0.15m).  The depth of the pond needs to be multiplied by two because the pond liner needs to go down one side of the pond and back up the other side.

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. I have used an overlay of 0.15m in my example calculations.

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

Multiplying the depth by 2 accounts for the depth on both sides of the pond. And, the same applies to the overlay. Planting shelves in your pond design don’t need to be accounted for as they won’t significantly affect the pond measurements.

The size of pond liner required can be calculated as: Maximum length + (2 x maximum depth of pond) x maximum width + (2 x maximum depth) with the overlay added into the length and width pond measurements. Or, take each measurement and use a pond liner calculator to do the calculation for you.

How to measure how much pond liner you need

Pond liner measurements for an L or U-shaped pond

For more complex pond designs such as an L-shaped or U-shaped pond, the easiest way to take measurements is to divide the pond into sections. So for an L-shape you would measure as a square + rectangle. The depth where the two liners will meet only needs to be added into the calculation once.

Or, calculate as a whole shape:

  • Measure the maximum depth
  • Measure the length of the two outer longest sides of the pond.
  • Multiply the maximum depth measurement by three and add it to the two longest lengths of your pond to get pond liner dimensions required. Box-welded pond liner fabricated from EPDM pond liner

Ponds with an island or raised plinth:

  • Measure the maximum depth of pond and multiply this by four,
  • Measure length and width of pond
  • 4 x maximum depth + length x width = pond dimension

Use our pond liner size Calculator to get the pond liner and underlay measurements you need to order for your pond design. For L-shape and ponds with a plinth you may want to discuss these with our pond experts first. You can phone us at Liners Online on 01526 399 033 for all your pond liner queries.