Water Gardens. When autumn arrives, there is a whole range of jobs which need to be done in the garden, and it is all too easy to forget the pond. Yet if you don´t take a few essential precautions now, you may loose most of your fish and some of your plants as well.
Obviously, what needs to be done will depend on the winter climate in your area. Wherever you are, though, it is a good idea to take a long hard look at your pond at this time of year and to sort out some of the potential problems before they occur.
Leaf fall causes the biggest problems for some pond owners. Once leaves have sunk to the bottom, they start to rot and pollute the water. Certain species contain toxins as well, which may harm your fish. The best way to reduce the amount of pollution caused by leaves falling into your pond is by covering it with a fine-meshed net at this time of year. It does not look very attractive, but it keeps the worst of the leaves out of your pond and makes quick work of their removal. During the summer, a layer of rotting plant material, fish waste, etc, will have built up on the bottom of the pond, so now is a good time to remove as much of this as possible. A fine-meshed net attached to a long wooden pole works well for this. Unfortunately, it is a dirty, smelly job, which makes you wonder at the efficiency of your pond filtration system, but it must be done. The regular use of an enzymatic cleaner is also recommended for the efficient breakdown of organic waste and detritus in the pond. this will help eliminate sludge build up and reduce pond maintenance.
After the first frost, most of the marginal plants will have had their foliage browned, and this should be cut down to water level. The oxygen weed will also need cutting back to a few centimetres of growth. this results in little cover left for the fish to hide in. It is a good idea to provide some large clay pipes on the bottom of the pond for fish hiding places. If these are unavailable, use some large pieces of slate resting on flat stones to make caves instead. Once all the surplus organic matter has been removed, a partial water change is a good idea. this can be as much as half the pond´s volume, but take care to add a water conditioner to remove chlorine or chloramines if these are present in your tap water. this water change is particularly important if you have a heavily stocked pond.