How do you know what and when to feed koi and goldfish in winter?

When its too cold for any plant growth, don't feed fish

There is no one rule since winters vary from location to location and certainly from year to year.  The temperature can change dramatically from day to day in small shallow bodies of water.  And, feeding mistakes can be fatal. What to do?

A good way to judge is by the plants in the pond.  Plant growth is regulated by both the light and the nitrogen cycle.  The nitrogen cycle is regulated by water (and soil) temperatures.  Therefore the state of plant growth or lack thereof is a good indication of the micro climate in the pond.  Since fish are cold blooded animals their body temperature mirror that of the pond.  So, when cool temperatures are slowing down the nitrogen cycle, they are also slowing down the fish’s ability to digest food.

Here are a couple of easy ‘rules of thumb’ for what to feed and when.

  • As long as the lilies are blooming, it is OK to feed high protein feeds such as Microbe-lift

    While lily pads have emerged and are still purple, feed cold water fish food

    Living Legacy Summer Staple or Variety Mix

  • When the lilies stop blooming, switch to the high carb, low protein feeds such as Microbe-lift Living Legacy Cold Water Fish Food, Wheat Germ
  • When the plant tops die back, or you’ve cut them back and then they are too cold to regrow at all, stop feeding all together.
  • When plants start to regrow, send up new shoots, then reintroduce the Cold Water Fish Food, just once a day.
  • When the lily’s leaves change from purplish to full green, then it is safe to switch back to the high protein Summer Staple or Variety Mix feeds.  Start with once a day.  As the days get warmer and warmer, you can add more feedings ( if your filter system can tolerate the added waste load).

Following these simple, easy to observe rules of thumb will help keep your fish happy and healthy throughout the winter season.

Once lily pads have turned full green its OK to feed high protein summer fish foods