Setting up ornamental fish breeding in a garden pond
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Category Gardening & Environment | Skills: Skill | Author: FMIS | Language : Language | Difficulty level : Medium | Time : 60min Share Take Challenge Add Activity


Many people who have a house with a garden want to constantly decorate and improve it. A frequently used element of gardens is a small pond in which there are fountains or streams of water and various varieties of water and marsh plants. In the end - having your own pond in the garden - there is an idea to have fish in the pond.

This action will show you step by step how to transform your pond in such a way that different species of decorative fish feel good in it.


The activity shall be implemented in 4 stages:

1. Do some research (e.g. on the Internet):

  • Explore what are the ornamental fish species that you can breed in your climate. Decide which fish species you want to have in your pond.
  • Find out about the requirements for breeding the type of fish you choose.

2. Prepare a pond for fish farming: clean the pond, fill it with water and adjust the acidity of the water to the requirements of the fish.

3. Buy ornamental fish and let them into the pond.

4. Evaluate your breeding and determine how it can be improved and developed in the future.


You will learn:

  • What species of decorative fish can be grown in a garden pond.
  • What are the requirements for breeding fish species in a garden pond.
  • How to search for information on the Internet about garden fish breeding, fish species and their breeding requirements.
  • What is the PH of water (water properties) and how it can be changed.
  • How to measure the volume of water in the pond.
  • How to calculate the necessary amount of ingredients to change the PH of water depending on its volume.


After completing the activity, you will achieve the following skills:

  • Perform simple measuring operations (volume measurement, mass calculation)
  • Use simple measuring tools
  • Perform simple mathematical operations
  • Develop manual skills
  • Develop of time organizing skills
  • Perform simple research observations
  • Developing interpersonal skills (independence, creativity,  resourcefulness, openness to new experience)
  • Organizing the workplace
  • Improving language skills by learning new words and how to use them


After completing the activity, the learners will achieve the following skills:

  • Reading and writing competence (careful reading with understanding instruction).
  • Mathematical competence (counting, using simple measuring tools, mathematical thinking).
  • IT competences (using information society technologies, using a computer, searching for information on the Internet, critical use of information contained on the Internet).
  • Creativity competence. 
  • Work planning and organisation.


  • Water
  • A preparation that increases or decreases the pH of water
  • Dirty water pump
  • Clean water hose
  • Soft brush for cleaning the bottom of the pond
  • Jar
  • pH meter
  • Line ruler
  • Ornamental fishes

How to set up ornamental fish breeding in a garden pond?

Preparation stage:
1.    Think about what species of ornamental fish you know.
2.    Check on the Internet what species of ornamental fish are suitable for growing in garden ponds, what they look like and which ones you like the most.
3.    Check on the Internet what the breeding requirements are for specific fish species, in particular, what PH of water is suitable for them.
4.    Check on the Internet what pH of water is suitable for plants grown in your garden pond
5.    Compare the pH of water suitable for fish with pH of water suitable for plants (if your plants require pH alkaline, and fish pH acid - you have to either change the fish or change plants in the pond)
6.    Choose a fish species for breeding in the pond (you can breed different varieties of species in your ponds, but check if these species tolerate each other. It is very important that the different varieties of fish can co-exist and not attack one another. You can find some information about it on the Internet or in a pet shop – they can help you select the varieties of fish that can co-exist).

7. Calculate how many fish you can keep (breed) in your pond:

a. Measure the Water Volume that fits in your pond. Remember that the Volume is the Length multiplied by the Width multiplied by the Depth. For each of these three dimensions it may happen that, for example, the width or length is different at different places on the garden pond, or the depth changes - in this case use the Average Value (how to calculate the average value - check on the Internet)

b. Check on the Internet what volume of a water should be enough for 1 fish of each species you have chosen (remember, the values of a water per fish given on the Internet or Pet shop, usually correspond to the adult fish. If you buy small fish, at the beginning will be little visible in the garden pond.

Over time, as the fish grow, they will be more visible in the garden pond. If you buy too many fish in relation to the small volume of a water in the garden pond, some of them may not survive and others will not grow fast enough.

c. Sum up the volume of a water for all the fish you want to buy and compare with the volume of the garden pond. If the volume of the pond is too small, you can either enlarge it or reduce the number of fish you want to have.

To assess how many fish your pond will support, estimate its surface area and allow 60sq cm of surface for every 1 cm of fish.  Since fish grow and breed, it is best to start off with around one-third of the theoretical maximum number.  For example, a 1,8m x 1,2m pond will, in theory, support 360cm of fish, equivalent to 36 individuals averaging 10cm long, but, in practice, you should have only about 12.

8.    Check online or in the Pet shop the availability of the fish you have chosen.
9.    Purchase a pH meter.


1.  Prepare your garden pond for fish:
a.    Remove the devices installed in the pond (e.g. reflectors, fountains, purifiers, etc.) from the pond
b.    Remove the pot plants from the pond (do not leave them in the sun, preferably place them in a bowl with water taken from the pond)
c.    Pump out the water from the pond using a dirty water pump
d.    Clean the bottom of the pond using a brush. Do not use any detergents or chemicals - only water and a brush. Remember to clean the bottom of the pond gently so as do not damage the bottom. Use a soft brush.
e.    Rinse the bottom of the pond with clean water and pump out the water
f.    Get water into the jar
g.    Determine the pH of the water using a pH meter.
h.    Knowing the pH of the water and knowing the volume of water in the garden pond, determine the amount of preparation for increasing or reducing the pH of water. In this way, you will adjust the pH of the water to the needs of your fish and plants
i.    Purchase the appropriate amount of preparation for increasing or reducing the pH of water you set in point h).
j.    Fill the pond with water to  1/3 of its depth
k.    Install in the pond the devices mentioned in point a). and plants refers in point b).
l.    Fill the pond with water fully (remember that the water does not reach ground level, because the earth will "drink" water from the pond)
m.    Put into the pond an appropriate preparation for adjusting  the pH of water to the needs of fish and plants according calculation you made in point h).

2.  Set up a fish farm in the garden pond:
a.    Buy ornamental fish.
b.    Buy fish food (remember, the size of the granules must be adapted to the fish size, for small fish - small, for large fish - it does not matter).
c.    Let the fish into the pond (immerse the entire vessel or sack with water and fish in the pond and wait until the fish have gone to the pond).
d.    After a few hours from the "settling" of fish – pour food on the pond surface  (remember that fish are fed once during the day, preferably in the evening).


3.  Show off your fish breeding with your friends and think how it can be improved and developed in the future.