A garden pond will be a marvelous asset to your garden. It attracts a great many wild animals and eventually becoming a miniature nature reserve. It is possible to have a pond which is self sustaining, requiring only the occasional maintenance to keep it in good condition.

A very large pond is often difficult to maintain and a very small pond may require constant attention as it may not be large enough to sustain itself. A garden pond does not have to be too deep and should preferably have a shelf about 12 “below the top of the side, to site aquatic plants. 

 

Try to locate your pond in a position away from trees, as autumn leaves that fall on the pond will rot and foul the water. Where this is not possible, you may have to net the pond when the leaves are falling.

Ideally, a pond should have some shade rather than being in full sun all day.

If you are going to run a pump, you will also need a source of electricity.

 

There are many ways to build a pond, the most common being pre-formed purchased form a garden centre, the size of which may be determined by the kind of transport available to get it home. Whilst a pre-formed pond is a ready made pond, a great deal of accuracy is required in digging the hole, getting the pond level and back filling with the soil you have taken out. Get it wrong and the pond will leak water at one end and mice and other vermin may find a home in the spaces between the soil and the pond sides.

An alternative method is to construct a pond to your own design, using a flexible liner made of Butyl, or a strong plastic. You must however, make sure there are no stones protruding from the pond sides that could puncture the liner, indeed it’s a good idea to place a layer of damp sharp sand against the sides, before you place the liner ready for filling.   

The third method is to dig out the shape of the pond, then set concrete at least 2” thick. This should be a permanent fixture on a clay soil, but can crack and leak on soft sandy soils. Furthermore, a period of time needs to elapse before fish can be released into a concrete pond as they are affected by the lime from the concrete base that can seep into the water.

Never use polythene sheeting as it becomes brittle and will leak in no time at all.

Water in a new pond will be green for up to four weeks until the water becomes “aired”.

If the soil you take out of the pond site is of reasonable quality, you can spread it around parts of the garden, or perhaps form it into a heap for a small waterfall. You should leave it to settle for a few months before doing this.

   

Ponds do not have to include fish, or even plants, but a pond without one or the other would be pretty boring and become stagnant in a matter of weeks if the water remained still. However, make sure your plants are established before adding fish to the pond as initially the fish want somewhere to hide. Until now they have never been in anything bigger than a fish tank and being transferred into a garden pond must be rather traumatic.

Always buy your fish from a reputable source. Never accept fish from friends or neighbors as they may have a virus which may in turn infect your fish. Goldfish, Orfe and if your pond is large enough, Koi, and many other types of fish will survive a British winter in a pond even if it freezes over. Refrain from buying Trench as they are bottom feeders and while they eat up the food which drifts down from the surface, they continually disturb the bottom of the pond and discolor the water.

 

There are all kinds of formula for calculating the numbers of fish for a pond and some can get quite complicated. A simple formula is to measure the surface of the pond and every square foot can accommodate half an inch of fish. For example, a 6ft x 4ft (24 sq ft) pond will maintain 24 x 6” fish, or 48 x 3” fish. However, if you have the right conditions, your fish will breed, so it’s probably better to start off with no more than half of your maximum quota.

 

 

When you buy fish, they are normally in half filled plastic bags. Float the bag in the pond for at least 30 minutes to allow the water temperatures to equalize before releasing the fish.

Feed your fish daily with a proprietary fish food. You can feed fish twice a day during the summer months, supplying them with only enough food that can be eaten in 10 minutes. Do not feed them after October, or before April. Fish metabolism slows down in cold water and they do not feed, or move around much during the winter months, merely surviving in a state of dormancy. Any feed will fall to the bottom of the pond and foul the water. However, on a warm winter’s day, fish can start moving around and take in feed if it is given to them. This is dangerous as the digestive system of the fish can’t cope if the weather turns cold again.

Fish can suffer from a range of ailments, including parasites, fungal infections and fin rot. You can buy proprietary preparations to treat these problems from most reputable pet shops that deal in aquatics.

 

There are several distinct groups of plants you can grow in or around a garden pond. Unfortunately, there are too many to list here, so you should ask at a garden centre dealing in aquatics for advice on the best plants for your pond.

Oxygenates are essential for keeping the pond healthy and clear and you should always have at least one submerged to absorb carbon dioxide and release oxygen into the water. They can multiply fairly rapidly and outgrow their space if not cut back. Remove the excess, which makes good garden compost when rotted down.

Water lilies are planted in containers that sit on the bottom of the pond and produce leaves and flowers on the surface in summer. They also help to shade the pond from the sun and inhibit the growth of weed. Don’t over plant, as they grow rapidly: one is sufficient in a small pond.

Marginal are planted in containers set in shallow water on shelves around the pond.

Floaters are flowering plants that simply float on the pond. Marsh plants can be planted at the edges of the pond, if the liner is extended and filled with soil to create waterlogged bog conditions.

Don’t use garden soil as it contains too many impurities and could contaminate the water. Your garden centre will advise on the best compost to use.

Spread gravel around the top of plant containers as fish delight in rummaging around the bottom of plants, disturbing the compost and discoloring the water.

 

The main problems in ponds are blanket weed, algae and fallen leaves.

Algae can be avoided to some extent by siting your pond away from the full sun. It is less of a problem when the pond is established with oxygenates and lilies.

Blanket weed is a bigger enemy as it thrives in healthy water. It can be removed by hand or with a stick, being careful not to puncture the liner. There are other effective methods to remove blanket weed, such as floating barley straw on the surface. You could also use chemicals, but the best method of cutting down on blanket weed is to keep the water moving. If you have a fountain and/or waterfall, keep it running at all times to aerate the pond. This will also keep ice from forming across all the surface of the pond in the winter

Leaves are a menace and if your pond is near trees, then the only way to keep the leaves out is to net the pond.

Ice rarely freezes in water beyond a depth of 18” in the UK and providing there are no rotting leaves giving off poisonous gas in the bottom of the pond and there is a hole in the ice to allow in oxygen, the fish will survive quite well for several months during the winter.

A rubber ball floating on the surface of the pond in winter can usually move around sufficiently enough to leave a hole in the ice thus allowing oxygen to get through, or use hot water from a kettle to make a hole in the ice. Never break the ice as this will affect the fish’s nervous systems and can kill them.

If you have a pump, a filter fixed to it, will remove algae and other particles from the water, although the filter will need cleaning on a regular basis.

With a larger pond, you can pump the water through a tank containing some kind of filtration product, although clean gravel will also do the trick and a tank full of hair curlers acts as an excellent filter. A central heating header tank for a small pond or a cold water storage tank for a larger pond is ideal. Bacteria that remove toxic waste will grow on the filters, thus keeping the pond clean and healthy.

If pollution remains a major problem, you can run the hose from the pump through an ultraviolet light to kill the algae and totally eliminate green water.

If your pond springs a leak it may mean draining it down to where the hole is, or draining it completely to affect a repair. If the latter is the case, move the fish and plants to a temporary tank.

You can purchase pond puncture kits to repair plastic liners form a garden centre that has an aquatics department.

A crack in a pre-formed pond is best fixed using a car body repair kit.

If you have a concrete pond, it’s probably better to drain it and add a plastic liner, rather than point up with cement, which rarely works.