When it comes to aquaponics fish species, the possibilities are wide. Some species grow fast, others taste good, but can we use ornamental fish for aquaponics?

What are ornamental fish? A fish is classified as ornamental when it displays nice colours. Ornamental fish are generally kept in aquariums or garden ponds.

Here below are 5 points you must know before getting ornamental fish for your aquaponics system:

1. Ornamental fish for aquaponics are perfect for vegan

An aquaponics ecosystem has for goal to produce fish and vegetables. An aquaponics setup produces approximately 10 times more vegetables than fish. However, the fish are part of the ecosystem and are very important. They transform the fish food into ammonia which is a source of protein for the whole ecosystem.

Vegans don’t consume fish and many fish keepers would consider the fish as pet and will not be comfortable harvesting them. In this specific case, the fish can simply be kept for their ornamental properties. It is very peaceful and enjoyable to watch colourful fish swimming in the backyard pond (aquaponics fish tank).

In this instance we will not choose the fish for their flesh quality but for their colours.

Keep in mind that most aquaponics fish tank backgrounds are dark. Even if you find nice looking black/dark fish, there are plenty of chances that you don’t see them once in the fish tank. In contrast, a colourful fish will look amazing on a black background.

2. The species selected must be adapted to water temperature and pH

The fish selection must not only be based on colours and patterns. Like for the classic fish, your choice of fish can only be among adapted fish to the temperature and pH of your water. Regarding the temperature we have 2 large categories of ornamental fish:

    2.1. Cold water ornamental fish

Those are fish with nice colours but adapted to cold waters (some of them can also live comfortably in warm waters). By cold water we mean anything between 0C and 23C. Among those fish we have the very famous Goldfish (and all declinations such as shubunkin, oranda, ranchu, ryukin, comet, fantail, black telescope, veiltail…) and of course, the Koi carps. But, there are also other types of less famous fish such as golden ide (Leuciscus idus also known as orfe), or golden trout. Golden trouts can be consumed and they are an excellent but they are also classified among the cold water ornamental fish. They look sensational on a black background pond (see the golden trout video here: https://aquaponicsrevolution.com/golden-trout-update https://youtu.be/Y3_n2nDxCD4)

    2.2. Tropical country ornamental fish

In this category we have all the colourful aquarium fish. They generally look very nice but most of them require temperatures above 24C. If you live in a tropical country and can maintain the water temperature above 24C, those fish are for you. The diversity is very wide but one thing you must pay attention to is the pH preference of the fish. Each fish species has a defined requirement in terms of pH. Some species such as African cichlids require a high pH while some others such as most Amazonian species, require a lower pH with very low quantity of minerals into the water. In aquaponics we maintain a pH around 7 so don’t choose fish with extreme pH requirements (more information about water pH here: https://aquaponicsrevolution.com/ph-control-in-aquaponics/


3. The legislation around your ornamental fish

Ornamental fish are not always native to your country. As you may be aware, there are some risk linked to the introduction of new species in the environment. They can sometimes colonise the local rivers, lakes and become a pest taking space of the original species. For this reason, some countries have decided to ban the import of certain species and classify them as pest. Those species are then illegal and can’t be kept alive.

In the state of Victoria in Australia for instance, Carps are classified as pest and it is illegal to keep koi carps in your pond (more information here: https://vfa.vic.gov.au/education/fish-species/carp). I highly recommend doing your due diligence before ordering your fish. Indeed, you expose yourself to huge fines if you decide to grow those fish against the law.

4. Fish food and drugs to use with ornamental fish for aquaponics…

When it comes to growing ornamental fish in aquaponics, we touch to an industry well established with plenty of products available. Certainly, you will find hundreds of ornamental fish species offered. But you will also find all the consumables that come with. I am talking here about fish food and drugs.

Those products are very well adapted to ornamental fish kept in aquariums. however, keep in mind that here, we are growing ornamental fish in aquaponics. By nature, in aquaponics we are growing food in an ecosystem. The fundamental of aquaponics means that any substance present in the fish food or drug used may have negative impact on your whole ecosystem. But not only! Some molecules present in the ornamental fish food are designed to enhance the fish colours. Not to be consumed by humans! Let’s be clear, even if we don’t consume the ornamental fish, the substance can build up into the plants and we would finally consume those substances with our vegetables. So please, stay away from aquarium fish food.

What about fish drugs? Do I really need to develop this point? The main principle in aquaponics is, don’t add any pesticide to the ecosystem. Does it respond to your question? As you may have guessed, the same principle as for aquarium fish food discussed above applies. There are chances to find those particles in the plants. You don’t want to consume those drugs with your nice homegrown veggies, do you?

5. Financial potential around ornamental fish

Growing ornamental fish can sometimes lead you to reproduce them. Some of those colourful fish are indeed “easy” to breed in aquaponics. Most oviparous fish such as guppies, mollies, xiphos… will breed if they are in good conditions. Those fish are tropical fish and require a temperature above 25C. If you have the chance to be able to maintain this water temperature all year long, then, you can generate a little income by growing and selling those fish to aquarium keepers. It is probably the easiest way to cover all your aquaponics cost and to produce free, sustainable, healthy and tasty food in your backyard J

So my big warning in this article is: Be aware that aquarium products are not designed for aquaponics.

you will probably be interested to discover Jonathan’s six steps to build and manage an Aquaponics system. Click here to access for free! Thanks and good reading 🙂