Pond Cleaning. How and when to clean the Garden Pond.

Most ponds will certainly need a good clean annually. Larger ponds will not necessarily need this annual clean. Generally be guided by the condition of the water and pond weed from the end of the previous year. Also take into account, and debris by way of fallen leaves in the autumn and winter months. If left in the bottom of ponds, they will decay and emit harmful gasses into the water.

Cleaning the Pond Skimmer - ready for the spring and summer season.

Spring is by far the best time to carry out pond cleaning, for the fish will be active, and pond plants more readily seen. Don't leave it too late until the plants are too large.

It is best to remove fish from the pond during a substantial clean-up for otherwise debris can get in their gills and generally cause shock and ill health. They should be stored in containers, previously filled with half fresh water and half pond water. Allow enough time for the fresh water to evaporate any harmful gasses and chemicals. Much will depend upon your own tap water area. Some have greater or lesser chemicals which can be harmful.

Try to remove plants before you lower the water level too far, starting from the marginals and gradually working through to the deep water plants. Oxygenating plants can normally be left until last, unless they are within easy reach. With the dense oxygenators, it is a good idea to leave them near the water edge overnight, to allow any water snails and the like access back into the pond. The same will be true of newts and small frogs etc.
After lowering the water as much as possible, finish the job with an electric pump. Drain all water out of the pond. Do not walk about on the bottom of the pod - especially if the pond has a butyl liner. Pond surfaces are easily damaged - even concrete. The stresses are now different to when the pond is full of water. It is not unknown for older less strong concrete ponds to break their back if there is a lot of soil moisture causing 'heaving' to the structural surface.
Once the pond is empty, then remove all the silt from the base, and give the structural surface a good scrub. use a long handled broom to do this rather than walk about in the pond. Also, use strong boards to form a bridge if possible, and work from them.
Once the pond has been cleaned, allow the structure to dry for a few hours. This will help to kill off any pests which have escaped the rigours of your scrubbing!
Refill with clean water - allowing it to fill slowly. At this stage, you can start adding the deep water plants, gradually working through to your marginals and oxygenators.
Do not start to introduce the fish until the pond has had time to clear and also 'breathe. This will ensure the least shock to the fish, and also ensure that their gills do not get clogged with minute particles of debris in the water. There is bound to be some disturbance of the soil from the planters - however careful you are in lowering them into the water again.