Changing the Garden Pond Water
Changing the garden pond water
A biological balance will be achieved in a well-functioning garden pond and this could be seriously disturbed by such operations as changing the water.
There are some situations, however, which make it necessary to change the water:
- if the surface of the water is covered with an oily film and many pond creatures are dying because rain water from your house roof has been conducted into the pond. Acidification of the water and a build-up of chemicals may be the result;
- if a concrete pond was not soaked in water for long enough before plants were introduced and toxic substances have leached from the concrete and are leading to the death of pond creatures.
In all cases, proceed very carefully and only pump out about half of the water, then add fresh water.
If the water level has dropped considerably’- particularly in the case of small ponds – during long periods of drought, you should allow fresh water to flow in only very slowly.
Water filters and aerators
In the case of garden ponds which have been professionally built, and in which there are no or only very few fish, there is no need for filters and water aerators. If they are present because you have a large number of fish in your pond, please make sure that the movement of water created by the filter device and aerator is not too strong. Lots of waves created by splashing water will disturbwhose natural habitat consists of still water. Surface plants, like water- or broad-leaved pondweed (Potamogeton natans), will not feel comfortable in such conditions. Never use chemical additives in filters!
Switching on the filter again:
If a filter is switched on again after a lengthy period of rest, it is necessary to conduct the first surge of water out of the pond. This is because the unused filter will harbour large quantities of organic substances that have been decomposed by bacteria and fungi. These decayed products would otherwise be pumped straight into the pond when the filter is turned on again, causing a lowering of the quality of the water.
Removing a filter:
If you decide to remove the filter completely, the transition period will take some time and the pond water will not be very clear during that period. The deliberate use of underwater plants which are able to absorb nutrients dissolved in the water through their leaves will accelerate clearing of the water.
Plant protection around and in a garden pond is usually a matter of taking preventive measures. The most important point is the choice of the right position for individual species of plants. Chemical plant protection agents should never be used in the pond as they will considerably and negatively affect the quality of the water and may be toxic to pond creatures. Do not use any biological plant brews or soap solutions either as these may cause great damage to the pond and radically disturb the community of plants and animals. Biological substances, like herbal brews or soft soap, can be employed along a dry pond edge in exceptional cases. Do not spray these agents in the direction of the water, however, so that none of them ends up in the pond. Completely avoid using any chemical agents on the pond edge. Even after they have been broken down in the, they are still present in a different form and may endanger life in the soil or pond.