Goldfish in the garden pond are a classic. Many people think about keeping the popular carp fish, which are not among the easiest fish and have some requirements for the pond and care. One of the most important aspects for the fish is the depth and size of the garden pond so that they can feel comfortable and live naturally. Garden ponds that are too small or shallow have a negative effect on vitality.

## Goldfish in the garden pond

The size of the pond is an important point when planning the artificial pond or the number of goldfish in the school. Goldfish are not the smallest fish and with good care they can grow significantly in size. In addition, due to their high spawn content, goldfish breed quickly in larger groups, which can quickly lead to a lack of space in your pond. This can cause the following problems:

- lack of oxygen
- stunted growth
- Goldfish jump out of the garden pond
- water dirty
- strong algae formation due to excess nutrients from fish excrement
- Eating enemies have an easy time

### size

In a garden pond of sufficient size, the carp fish (Cyprinidae) can thrive and are protected from most predators such as cranes, cats and foxes. In addition, you can decorate a larger pond much more easily, because Carassius gibelio forma auratus really thrives in a pond with lots of plants and hiding places. They will do well if the bank area is sufficiently planted and the fish have a large, free area in the middle at the same time. For this reason, you must provide the animals with sufficient space. The space requirement is calculated using the following values:

- Goldfish Length Centimeter
- number of fish
- 3 liters of water per linear centimeter

On average, goldfish are between 30 and 35 centimeters long. You need at least five specimens, as goldfish only feel comfortable in shoals of this size and larger. If the sample calculation is based on a swarm with ten adult specimens, the calculation is as follows:

**35 (length centimeters) x 10 (number of fish) = 350 (total fish length)**

Now the calculated fish length is multiplied by a factor of 3, which is 1,050 liters of water required in the end. On average, you need around 100 to 105 liters of water per goldfish to meet the requirements of the animals. However, this quantity is not the only value you need to consider. There are two other points that must be offset against the required amount of water:

- Water requirement plants: 1,000 l
- Space required for offspring and other pond inhabitants: 1,000 l

In the end, with a swarm size of 10 goldfish, including the aquatic plants, the possible spawn and other pond inhabitants, you will reach a size of 3,050 liters. Even narrow garden ponds can be inhabited by the goldfish without any problems, as long as the longest side is not smaller than 150 centimeters. The garden pond must also not be too shallow, which is explained in the next section.

### depth

The depth of the garden pond is essential for the fish, since water that is too shallow does not meet the goldfish's requirements for the artificial habitat. A garden pond with the ideal depth has many advantages that have a positive effect on the vitality of the fish:

- numerous retreats
- cooling over the summer
- does not freeze through the winter
- easier cleaning

Especially the advantages in terms of hibernation should be mentioned here, because you don't have to relocate the fish and they don't suffer from the winter cold because they stay deep enough in the water. Even a lack of oxygen over the winter is prevented by the depth, especially if you use tools such as an ice preventer. You should keep the following points in relation to depth in mind:

- Minimum depth: 80 centimeters (regardless of the swarm size)
- good range between 100 and 150 centimeters
- ideally 150 centimeters or deeper

A depth of more than 150 centimeters is of course not possible for many garden owners. For this reason you should try to keep the pond depth in the range of 100 to 150 centimeters in order to be able to offer your goldfish enough space. The deeper the garden pond, the more goldfish you can keep. If you are a fan of goldfish and want to keep different varieties in one pond, deeper ponds are always preferable.

* notice: If you live in a very warm region or the pond is constantly exposed to the sun, you should definitely make it a little deeper.* Since the upper layers of the water can heat up quickly when they are in direct sunlight, the goldfish have sufficient opportunities to retreat when they can swim downwards.

### volume

The volume is an important quantity that allows you to calculate the final amount of water according to the size of the pond. For this reason you will find a list of the typical pond shapes and how to calculate their surface area in order to calculate the volume. A calculation in meters is ideal, as this makes the calculation much easier. The following formulas are used here:

**Square and rectangle: side a x side b = area****Circle: Radius² x Pi = area****Ellipse: semi-axis a x semi-axis b x Pi = area**

After you have calculated the area of the shape, you need to multiply it by the depth of the planned pond:

**Area x pond depth = volume**

The final volume is given in cubic meters (m³). You need this value to calculate the final amount of water, which is given in liters (l) for the pond. So you need to convert cubic meters to liters:

**1 m³ = 1,000 l**

It is important to take the sloping shape of many ponds into account as a precaution. For example, if you have a specific shoal size in mind, but the volume of the pond is only just within that range, you should either create a larger pond, reduce the planned shoal size of goldfish, or choose a smaller species. Because ponds narrow in depth and reduce the actual volume. This means that the fish have less space available, but this is very difficult to calculate. Therefore, you should always have significantly more space than fish in comparison.

**tip**: If you have a pond made up of several shapes, you must calculate the volume from several parts as well. To do this, calculate each shape individually and add up the volume to get the required amount at the end.