Fish are now semi dormant so they should not be fed.
The established plants have been cut down and this season is unsuitable for planting aquatics.
Container grown bog plants can be planted at this time if it is a mild spell and the ground is reasonably dry.
The only time the pond will need attention is if there is a very cold snap. Obviously small ponds will be turned into blocks of ice, which will mean death for any fish and most plants including water lilies. You can use wooden boards and sacking for a short time if arctic weather is forecast but the flora and fauna should not be left in the dark for too long.
In a larger pond neither plants nor fish are directly killed by an ice sheet above them but if it prolongs there can still be a serious problem. If an ice sheet is on a ponds surface for more than a couple of days, the gases produced from decaying organic matter - marsh gas - can build up to a toxic level. This can be deadly to fish and plants, so the best thing to do is create a hole in the top of the ice which goes down into the water. Do not try and crack the ice with a hammer or blunt object as this can cause harm to the fish. Instead, get a pan of boiling water and melt the whole open. Try to remove about 1 inch of ice. The hole must be kept open for as long as the ice is thick on the top. By creating the hole all of the gases can escape.
If you are very worried about the freezing weather, you can purchase a low voltage pond heater. This is connected to the mains and will keep the pond just above freezing. Even with a heater in place it is still a good idea to check your pond regularly.
In a concrete pond, you can float a wooden plank in the pond to take the pressure off the ice sheet and when the pond is not frozen you can run the pump every fortnight or so just to keep the water freshened.
Now is also a great time to look for new ideas and plants for your pond and plan for the year ahead.
