Each stage to build a wildlife pond is explained in easy to follow detail here.
You are now ready to fit the liner
Rubber liner is more flexible than plastic and I find it the easiest to fit, but it is more expensive than the plastic ones. I also fit a fabric underlay between the liner and the sand. Amazon stock a large range of different pond liners, underlay and sizes.
This is how to calculate the size of the liner
Length of liner = twice maximum depth of pond + maximum length of pond + 1m (3' 3") excess.
Width of liner = twice maximum depth of pond + maximum width of pond + 1m (3' 3") excess.
Puddling clay. An alternative really natural way to line a pond is to use puddling clay.
This is easier to do on a warm day, the liner will be more flexible and easier to fit and shape.
Pond plants are essential to achieve a correct water balance and provide surface cover in your garden pond. Without them your water will probably resemble pea soup, as algae will grow prolifically. Plant foliage absorbs carbon dioxide and minerals from the water which 'starves' the algae. About half of the water surface should be covered with foliage to achieve this balance.
Pond plants fall into four basic groups. Each is important to the health of your pond. The groups are oxygenators, floaters, marginals and deep water aquatics.
Floaters are pond plants you drop into the pond. Their roots are submerged and their leaves and stems float either on or just below the surface. They provide surface cover. Many of them sink and overwinter at the bottom of your pond. Water hyacinth is a flowering 'floater' but only in a good summer.
Other floaters include frog-bit, water lettuce and water soldier and fairy moss. Duck weed is also a floater, it is invasive and best avoided. Once you have duck weed established in your pond, you will never get rid of it.
Deep Water pond plants
Deep water plants need to be planted at least a foot deep. Their leaves help to shade the pond and keep your pond life cool, provide shelter and help keep the water clear by limiting the sun's rays.
Water hawthorn is fragrant, long flowering and will tolerate moving water and some shade. Golden club needs to be planted in a deep tub. Has distinctive yellow and white flower heads.
Once again to many to list here its worth a visit to a local pond center. The water lily in the picture is one I have planted in my pond at home.
Marginal pond plants.
Marginals are planted on the margins of the pond. They include Marsh marigolds, pickerel weed and many more. Plant them on the shelf we built around the pond.
They look good and provide some protection for your frogs and other pond creatures from predators. The Mix of Marginal pond plants in the picture are also perfect for bees & other pollinating insects.
I remove marginals from the baskets, keeping the root in as much compost as I can and plant them on the shelf held down by stones, looks more natural.
Oxygenating pond plants for natural ponds.
Oxygenators are very important for keeping the water clear. Their roots and stems are submerged and usually the leaves are submerged as well. They are often bought in bunches. You will need one bunch for each 3 sq. ft. of surface area. Most oxygenators do not flower, but two exceptions are water violet and water buttercup.
Water milfoil is ok for a small pond. Willow moss is evergreen and slow growing. Hornwort and curly pond weed (elodea crispa) are effective oxygenators.
The pond oxygenting plant in the picture is not invasive so Ideal for ponds of all sizes, probaly the reason it is the top seller on amazon.