Fall and Winter Fish Care

What You Need to Know to Keep Your Fish Healthy

There are certain changes you need to make in how you care for your pond and fish as the temperatures decrease. Check out the tips below, to see what you know or need to learn about your pond and fish.

Feeding Fish

Change the type of fish food you are using. When the water temperature falls to 65 degrees, start using low temp fish food. Low temp food digests quickly, but helps get your fish ready for a long winter.

Stop feeding your fish when the water falls below 55 degrees. Once the water gets this cool, fish stop digesting food. You don't want that food to remain in them all winter! It could kill them. Resist the temptation to feed your fish over the winter when the water warms for a short period of time and they begin to move around.

A hole in the ice made from an aerator

Keeping Them Healthy

Keeping your fish outside in their pond during the winter is normal. Now you may be shocked that I said that because either 1.) you never even considered bringing your fish inside or 2.) you are thinking I couldn't possibly leave them out in the cold. But we have plenty of customers that bring their fish inside every winter. Remember this, as long as your pond has a deep pocket that is 18" to 24" deep, you have a hole in the ice for gas exchange, and your pond is fairly clean your fish should winter just fine.

What does that mean... gas exchange? We want toxic gases (carbon dioxide) from decaying organic matter and fish respiration to get out of the water and we want oxygen to get into the water. Your pond does not have to be ice-free, just a small basketball sized hole will do. To achieve this, follow these steps:

  • In some ponds, the waterfall itself may be enough to keep the water from freezing most of the winter. Beware, however, if you have a large waterfall drop directly into the pond (there is no creek or series of drops before the water falls back into the pond) the large drop may stir up the warm bottom of the pond. It's important not to "stir-up" the water on the bottom of the pond where it is the warmest. That's were your fish will want to huddle. If this is your situation, you may want to shut your waterfall down for the winter.
  • Use an aerator with the air stones or plate close to the water surface to agitate the water enough not to freeze. If you already have an aerator in your pond, make sure the air stones are brought up to just under the water surface so the pond bottom isn't disturbed. 
  • Have a floating deicer for the coldest parts of winter. A floating deicer is an electrical appliance that warms the water around the deicer to just above freezing. It has an internal thermostat that turns the deicer off and on according to water temperature. When the temps get into the single digits or below, an aerator may not be enough to keep the ice open. It's good to have the deicer for backup.
  • So why bother with the aerator and not just use a deicer only? It boils down to electrical consumption. A deicer uses 250-1500 watts of electricity depending on your pond size. An aerator uses only 4-8 watts!! Also, historically, aerators have been more reliable in polar temperatures.

So before winter, make sure you have a thermometer for the water temperature, low temp fish food, a deicer and possibly an aerator. It's also good to have some dechlorinator on hand all year for water top-offs if you are on city water. 

You also need to decide if you are going to keep your pond running all winter or shut it down... read that here. Please let us know if you have any questions about fall care or fish care. We are here to help.


Popular Posts