Every year more gardeners give in to the temptation to install a garden pond. It is easy to understand why. With its qualities of reflection and movement, water is more alluring than any other point of focus. It also creates a habitat for plants that would never thrive in ordinary soil, and fish add another attraction.
 Latest estimates suggest that about 2.5 million or some 10pc of British gardens contain a pond - and that's not including mini-water features. But do their owners all realise that a pond is not just for summer? Probably not. The problems of a neglected pool become apparent the following year, so it's best to assess the situation now and take action soon to avoid water torture. In most cases this summer's warm weather will have benefited both fish and plants. The fish, for example, will have had plenty of opportunity to build up their food reserves, which will enable them to survive through the winter. Fry, the tiny young fish, are susceptible to starvation during the winter if they have not grown sufficiently. On the other hand, the growth and survival of fish and fry can cause a problem with overstocking. So check the numbers and size of fish in your pond - maximum is 75cm of fish length for every square metre of water surface area (3in per square foot). Autumn is an ideal time to give your pond its annual overhaul and remove any debris which has accumulated during the year. The cleaning is best done before the water temperature falls below 10C (50F) as the fish will still be active and are unlikely to suffer any ill effects from the disturbance. The pond should be partly drained, down to about 50pc of the water. Use a siphon, pump or pond-vac to remove water and debris from the bottom. If a normal pond pump is used, large particles of debris should be removed beforehand with a fine-mesh net and the pump cleaned afterwards to prevent it from becoming blocked. The modern kinds of pump that process larger pieces of debris make the job easier. If the pond is particularly dirty, move the fish to a holding container and completely drain and clean the pond. Keep the container in the shade and make sure the fish cannot jump out. When refilling the pool with tap-water, treat it with a good-quality conditioner such as TetraPond WaterSafe which neutralises potentially dangerous chlorine from the public water supply. Chloramine, another chemical more harmful to fish, is occasionally added to the mains supply by some water authorities in summer. If you suspect this, check with your local water authority and, if necessary, treat the water with TetraPond AquaSafe Advanced, which not only neutralises chlorine but also coats the fishes with a layer which protects them against chloramines and other undesirable substances. However, if a pond is cleaned and refilled in early October, there should be no chloramine in the water supply. With the pond water at a low level during cleaning, you have an ideal opportunity to remove dead leaves and spent blooms from aquatic plants before they sink and start to decompose. Failure to do so can result in large quantities of decaying material in the pond which could adversely affect the water quality. There are other points to watch, too. Prepare a fine-mesh net to stretch over the pond and prevent leaves falling into the water. Although the net may look unsightly, it only needs to be in position while the leaves are falling and is far easier than removing the leaves from the pond by hand. The net can be left on throughout the winter to keep hungry herons off. Sudden water temperature changes can harm fish. These can happen on clear, frosty days throughout the autumn, winter and spring, when the daytime temperature may be as much as 10C (50F) warmer than at night. Such problems are less serious in larger ponds or where there is a water depth of over 45cm (18in) since the larger volume of water takes longer to warm up and cool down. A prolonged water temperature of 0C-2C (32F-35F) can also cause problems for the fish. A reasonable water depth and little or no circulation will protect the fish from these conditions. Should pumps and filters be kept running throughout winter? There are two points of view on this. One is that fountains and filters should be switched off as soon as feeding the fish stops, when the water temperature falls below 8C (46F). The idea is to prevent cold surface water being mixed with the warmer water at the bottom where the fish are taking refuge. This has the advantage of providing an opportunity for pump cleaning or servicing. However, the temperature of water less than 45cm (18in) deep is unlikely to vary much at different levels, while ponds of more than 60cm (2ft) offer deep-water protection to fish. A complete switch-off can also cause a problem with external filters. The bacteria which occur naturally in water take time to populate the filter in sufficient numbers to purify the flow easily. Although their numbers are reduced in winter some will remain alive in an active filter ready to multiply in spring. If the filter is turned off, they will die and need to be replenished from pond-water pumped through. So the second option - and probably the best - is to reduce the flow rather than stop it altogether. This is certainly best in ponds that are heavy on fish and light on plants. Most pond plants, whether deep-water or marginal, are extremely robust and need no special protection in winter. The exceptions are exotics, such as the floating plant water hyacinth, which can be protected in a bucket of pond water in a cool greenhouse over winter or simply replaced in spring. Plants with excessive growth, such as water mint and marsh marigold, should be trimmed, especially where they are shading less vigorous species, and those with roots bursting through their containers can be divided in early autumn. | 
Travel, Entertainment & leisure
Professional Services
Health
Home Style
Home Improvements
Fashion & Weddings
Gifts
