Filters

• 1). Install a pond filter to keep the water clean of leaves and debris.
  
  
• 2). Inspect your pond filter daily when leaves begin to fall and keep it cleaned out.
  
  
• 3). Prevent buildup of ammonia and gases from decaying organic matter by removing leaves from the filter and skimmer. Add them to your compost pile.
  
  

Top Net

• 1). Stake a net over your pond before the leaves begin to fall. Keep the net stretched tightly above the water surface if there are fish in the pond. If you have evergreen trees, use a net with a fine mesh to trap the needles. Set the net above the surface so leaves won't decay in the water. Use large floating balls to keep nets above water on large ponds.
  
  
• 2). Inspect the net often to make sure the edges are secure so the wind won't catch them and allow leaves underneath.
  
  
• 3). Leave the net on the pond over winter to keep leaf and other debris out of water when the filter is turned off in cold climates.
  
  

Skimmers and Nets

• 1). Check the swimming pool supply section in hardware stores for short- and long-handled water skimmer nets. These sweep leaves and debris off the water surface and bring them to the side for disposal.
  
  
• 2). Remove bottom leaves by roiling the water so they are suspended and then capturing them in the net. Get nets with telescoping arms long enough to reach all spots where leaves collect in your pond.
  
  
• 3). Use a gravel vacuum to siphon the leaf debris from the pond bottom before it pollutes the water. Suck the sludge into the vacuum filter, where it is removed from the water.
  
  

Bacteria

• 1). Remove leaves and built-up debris in your pond with beneficial bacteria products made to digest organic matter with cellulose enzymes.
  
  
• 2). Add one quart of liquid bacteria and two 2-ounce water-soluble packets of cellulose enzymes, a cold-weather bacteria and cellulose-producing bacteria to your pond.
  
  
• 3
  Fish can live through the winter if the pond water is clean.koi pond image by MPH from Fotolia.com
  
  Use the enzymes in the fall to break down the bottom sludge all winter, according to KoiPondFever president R.C. Moore.