Winterizing your Pond

Fall Cleaning:  Fall is an ideal time to clean your pond.  If you do it while the fish are still active, they are not likely to suffer any ill effects, and will have a healthier winter environment.  Some experts recommend removing up to 50% of the water, using a pump or pool vacuum to remove water and debris from the bottom.  If you do this, don’t forget to add the dechlorinator and chloramine remover.

If you have trees near your pond, covering the pond with netting will save a lot of work. Use poles or other objects to keep the net above the water.  If the net is on the water, it will sink into the water with the weight of the leaves and snow and be very difficult to work with.

Another option is to build a dome over the pond. This will keep the leaves and snow out along with retaining heat in the pond.

Fish and Critters:  As the water temperature begins to drop the fish will become less active.  We need to feed a wheatgerm-based food when the water temperature drops below 60 degrees,  This will be easier for the fish to digest.  When the water temperature drops below 50 degrees we need to stop feeding the fish all together, even on warm days when the fish are looking at you and begging for you to feed them.  We will not start feeding again until the water temperature is above 50 degrees again in the spring.

You must keep a hole in the ice throughout the winter for the fish to survive!  They must have  enough oxygen to support life.  Deadly gases (Hydrogen Slulfide) build up under the ice as the organic matter accumulated over the year decays and uses up the available oxygen.  If the pond freezes over completely, oxygen to replace that being used is not available and the lives of the fish are at risk.  There are several methods for keeping a hole in the ice.

  • Keep a pump running 2-3 inches below the water surface to move the water enough to prevent it from freezing.
  • Place an air stone at the bottom of the pond to allow air to rise to the surface, this will keep a hole in the ice and also break the strata layers in the pond to exhaust off any gasses that are building up.
  • Use a floating pond heater.  Heaters have a thermocouple in the unit that will turn the unit off when the water temperature reaches the set level.  In most cold climates the heater will run non-stop during the winter months,  this can be very expensive.  The use of a product called a Thermo-cube that uses the outside air temperature to turn the heater on and off will save on energy costs.

If the pond does freeze over DO NOT try to break a hole in the ice!!  The blows will cause shock waves to pass through the water, causing damage to the soft tissue of the fish.  You can place a pot of hot water on the ice and let it melt through, make sure to tie a string to the pot or it will end up at the bottom of your pond!

Other critters, such as tadpoles, frogs, turtles and snails seem to find a place to live during the winter months, without any help from us. You need to make sure that any critter that is in  your pond is winter hardy, there are some tropical animals that will not survive the cold and need to be brought inside if you want them to survive.

General:  If you are planning on keeping your waterfall running during the winter you will need to make sure it is designed for it.  If the sidewalls of your stream are to shallow the water could freeze and run over the liner.

If you are planning on shutting down your system make sure to drain all of the plumbing. If you have a check valve at the pump you will need to open that valve so that all the water will drain out of the system.  The pump will need to be removed and stored in a bucket of water so that the seals of the pump do not dry out.  Make sure to winterize any auto-fill systems also.

Check the water level on your pond on a regular basis, water will need to be added when water was used to make ice and for evaporation. If you have to add more than 10% of the water volume then a dechlorinator will need to be used.