A pond with an established culture and a natural balance between plant and animal life will require less attention than one where there isn’t, but even nature ponds need maintenance to ensure they remain healthy. Here are a few tips to help maintain your pond through the seasons.
Small wildlife friendly ponds need cleaning about every five years, large ponds about every 10 years.
Natural ponds and man-made ponds designed and built to attract and sustain wildlife should not be cleaned to often and never completely cleaned out at all. It can take years to develop a balanced ecosystem and just a day to destroy it. It's a fine balance between cleaning a pond and ruining it.
Equipment you will need to clean a pond.
I found this pond cleaning kit on amazon inexpensive and does the job.
Pond cleaning tips
Things to do in autumn and winter.
Looking after garden ponds in winter.
It is important to keep your pond from freezing over. If the surface remains frozen for more than a few days it causes a build-up of gases and the oxygen levels to drop, killing your pond-life and fish. A frozen pond will also cut of the supply of drinking water for birds and other wildlife.
if you have a pump leave it on, the water movement will help keep an area free of ice and circulate the water helping keep up oxygen levels.
If you don't have a pump running keep a hole open in the ice by pouring on boiling water from a kettle, or if the ice isn't too thick poke holes in the ice with a broom handle or sharp stick, another way is to use one of the small floating pond-heating units.