One of the biggest problems in the Autumn and Winter is when leaves begin to fall from the trees above. If these leaves get in the pond and decay it will throw off the ecological balance of the pond. Remove by using a net to skim the leaves off the surface of the pond.
As the water temperature falls we should be feeding our fish less as their metabolism slows down. Once the temperature drops below 10 degrees C you should stop feeding altogether. Cold-water fish such as Goldfish and Koi cannot digest food properly below these temperatures. They will happily munch on algae and other natural foods if the water does warm up occasionally.
Do not allow your pond to completely freeze over, make sure you have a small area free from ice, as organics decompose in the pond they can produce toxic gases that can become trapped in the pond if it is covered by ice for more than a few days. Defrost a small area using warm water.
As plants are starting to die back, any dead and dying leaves should be removed,
place plants deep enough in the pond to keep the roots from freezing.
PUMPS & FILTERS
It is advantageous to keep your pump and filter running through the winter. The bacteria in your biological filter will not be active at low temperatures but it will remain alive as long as you keep it supplied with oxygenated water. When spring arrives and the water temperatures begin to rise the bacteria can start to work immediately keeping the water quality healthy for your fish and helping to control the algae.
Pond Feeding Guide
Many, many people only buy one kind of fish food and feed that to their fish all year round. However, this is not necessarily the best option for the fish or your pocket. Pond fish extract different nutrients from their food at a different temperature. In the case of protein the uptake of this nutrient is limited during the cooler months and much higher during the hot summer temperatures. Foods have now been developed with this in mind and Wheatgerm foods which are low in protein but more easily digested, have been developed for Autumn, Winter and Spring feeding; whilst growth foods, which are high in protein are available for summer months. Below is a rough guide of what to feed and when.
You should only feed your fish enough food to allow them to feed for five minutes. Any more will be wasted and end up as waste in the pond. If a fish is fed until it is full, 30% of fish food will come straight out as waste. The five minute feed can be given four or five times a day, at regular times during the day in the summer months.