The goldfish has been one of the most popular non-domestic pets of humans for over a millennium and is offered in numerous breeding forms. The freshwater fish are originally found in lakes and are kept by pond and garden owners in a wide variety of living conditions. Since the fish cannot withstand frost, Carassius auratus needs intensive preparation in order to be able to overwinter. Methods for the pond and in the house, such as rain barrels, are available to you.
Hibernation outdoors
When is wintering in the pond possible?
Cultivated Carassius auratus will not survive the winter in the garden without preparation. You need at least a water temperature of 4 °C to survive the cold season if you don't want to keep the fish in barrels or other containers. If the temperature in the pond falls below this value, your goldfish population must definitely move to suitable premises over the winter. There are three points that make wintering in the garden pond possible:
1. Depth
The depth of the garden pond is particularly important if you want to let your goldfish overwinter in it. The lowest temperatures prevail at the surface of the pond, which is why the water can freeze there. In order to reach the minimum temperature of 4 °C, which is necessary for the survival of the fish, the garden pond must have a minimum depth of 80 centimetres. From this depth, the temperature is a solid 4°C. Of course, a deeper garden pond is always better, but this is easily enough for the goldfish.
2. Adjustment period
You should never keep goldfish in a garden pond over the winter if they haven't been for at least a period of time six months live there. The fish need this time to get used to the garden pond, to find their way around and to make themselves comfortable there. Within the first six months, the onset of winter would be fatal for the fish, which have adapted perfectly.
3. Bubble stone
The bubble or aeration stone is another important element to guarantee the survival of the fish over the winter. On the one hand, it ensures that oxygen gets into the water and used gases are routed outside, and on the other hand it creates a permanent hole in the ice. This hole directs foul gases out of the water, which keeps the fish from suffocating.
If you can't make any of these things happen, you'll need to get your indoor goldfish population through the winter. There is no way around it, otherwise the garden pond will become a real trap for the fish.
tip: Do not toy with the idea of using a circulation pump over the winter instead of an aerator stone. The circulation ensures that the temperature in the garden pond drops even more and your goldfish freezes to death within a short time.
Overwinter in the pond
preparation
Overwintering in a pond is particularly suitable for large goldfish populations, as they generally have a garden pond that is deep enough. The preparation is particularly important here, the rest is done by the winter. Follow this guide to prepare:
1. Remove dead plant remains
In late fall, before the first frost, remove all dead plant matter and debris from the pond, as well as leaves that have fallen to the surface or sunk into the pond. Thoroughly cut back your aquatic plants at the same time. The best time is easy to read from the climate diagrams in your region. As soon as the temperatures approach 8 °C, take care of the garden pond.
2. Remove bottom mud
Then remove excess bottom mud, as this can significantly restrict the air supply over the winter. If you don't have a pond sludge vacuum cleaner yourself, you can hire one from a specialist company. Depending on the suction power, these are available for rental fees of 25 to 35 euros per day.
3. Ice preventer
Now install the ice preventer, i.e. the bubble stone. This should best be placed in a corner of the pond that is not under trees. This will prevent leaves from collecting on the hole, which would cut off the airflow. Make sure that the aerator stone cannot be turned off or fail throughout the winter.
ice preventer
4. Turn off pumps and filters
Next, turn off the circulation pump and filter system. You should not switch them on again for the entire winter. Fountains should also be switched off, as they also cause the water to circulate.
manual
Now the garden pond is prepared and the fish are ready for the winter. Proceed as follows when hibernating:
1. Reduce feeding
From a water temperature of 8 °C, the fish slowly go into their hibernation. From now on, stop feeding, because the animals retreat to a corner of the pond to hibernate.
2. Keep ice hole clean
Over the winter you should remove snow and leaves from the hole created by the air stone.
3. Check fish activity
On warmer winter days above 8°C, check to see if the fish are getting active. In this case, feed some sink feed to keep the animals on the ground. When checking and feeding, be as quiet and calm as possible so as not to disturb the fish. Stress over the winter is not good for the goldfish.
4. Increase feeding
You can feed again from March, but only when the temperatures rise. Start with a small amount and gradually increase over a period of up to eight weeks. Usually the normal amount of food is reached from mid-May after the ice saints.
Fish food pond sticks
Overwinter in the house
Overwintering in tons
preparation
Overwintering a goldfish indoors requires just as good a preparation as overwintering in a pond. However, you do not have to prepare the garden pond here, but rather the container and the winter quarters. You should never keep the animals in a classic aquarium in your living room. This not only upsets the rhythm of the fish, but also leads to stress. The winter quarters should be as follows:
- cool
- sheltered from the wind
- quiet
- Temperature: 4°C - 8°C
The most suitable unheated Basements, garages and the like. In these, the fish are rarely disturbed and the temperature does not fall below 4 °C. Once you have found a suitable room, follow these instructions:
1. suitable containers
First, get the tank that will be the home of your goldfish population for the next few months. An opaque container is used for this, on which a plate, also opaque, can be placed. As a result, it is not too bright for the animals. Large plastic tubs or rain barrels are well suited for this. Depending on the size of your goldfish population, you may need several such cold water tanks.
2. Pump & Filter
Now equip the tank with a circulation pump and a filter so that the water quality remains stable over the winter. To do this, simply drill holes for the hoses in the side of the bin just below the rim and insert them into the bin. As a result, you do not have to guide the hoses over the edge into the container.
3. Fill container
Then fill the container with a mixture of 1 part pond water and 1 part tap water. The pond water allows the fish to get used to their temporary home more quickly. Spread a thick layer of sand on the ground for extra warmth.
manual
1. Relocate fish
Get every goldfish in before the first frost, at the latest from a water temperature of 8 °C. From this point it is important that the water temperature does not drop too quickly, which would lead to the death of the fish.
2. Cover container
After relocating the goldfish to the container, cover all but part of it with the plate. As with keeping them in a garden pond, a hole or gap should always remain open. Watch the water temperature throughout the winter. This should always be within the range of 4°C to 8°C, not higher or lower.
3. Feeding
They are not fed over the winter either. Offer the first feed supplements to the fish from around March and increase them at careful intervals over a period of four to eight weeks.
4. Fish back into the pond
From mid-May, around after the Ice Saints, there is no longer a threat of frost and you can put the animals back in the garden pond.
Tip: Be careful when you choose a garden shed as winter quarters for the fish. These should be tight so that no draft penetrates the container, which could cool it down.
illness
Despite good preparation, a goldfish can fall ill during the winter. In this case, proceed as follows:
- Remove fish from the garden pond
- Fill the container with 1 part pond water and 1 part tap water
- Spread sand on the floor
- Place fish in containers
- warm up over 2 days
- then administer medications prescribed by the veterinarian
You can recognize sick animals by the fact that they swim on the surface over the winter or keep drifting on their side. Therefore, check your goldfish regularly over the winter.