Trout & Salmon in Aquaponics
Welcome to our meet the fish series where we will take you through the different types of fish found in aquaponic farming! We want to introduce you to each fish family and the different species that fall under them. Moreover, we want to provide you with all the information needed to decide which fish suits your wants and needs in your aquaponic journey. Therefore, without further ado, let’s talk about Trout & Salmon in Aquaponics.
Why have we grouped these together you ask? Well, trout is just one of the many species that actually fall under the Salmonid fish family. Three species of trout are used in aquaponics: Rainbow Trout, Brown Trout and Golden Trout. However, Rainbow Trout is the most commonly used species in aquaponics.
Rainbow
Oncorhynchus mykiss is commonly found in a cooler climate. Which, in South Africa, can prove to be a bit of a challenge. However, that does not mean you should avoid farming trout! If you can manage your temperature by keeping it around 18°C, trout can be a great species to farm in aquaponics. Its fast growth rate is favoured over a period of 5 months, they can grow from 110g – 660g! We recommend a stocking density of 15-20kgs/m3.
Some challenges
Unfortunately, farming trout in aquaponics can be slightly challenging. Trout are carnivorous which means that they have a higher metabolic rate and therefore, require higher dissolved oxygen levels and cleaner water. You’ll need to have more cycles and water changes which could mean including bigger pumps in your system design. Rainbow trout is favoured as one of the strongest trout species in the family and we recommend starting here should you be interested in trout farming.
A friendly tip: If your temperature gets out of hand for whatever reason, make sure to stop feeding at 20°C. This is because trout are susceptible to bacterial gut infections that can cause indigestion. If not monitored you’ll, unfortunately, have some belly up fishies.
Where to find
Trout spawn during the winter and therefore this is when eggs and fry are readily available from local suppliers. If you are new to aquaponics, we recommend purchasing fingerlings as they are more adaptable. Hatching trout eggs is a relatively straightforward process and requires clean water at a temperature between 9°C and 12°C. When purchasing trout you have the option of choosing between mixed-sex, all-female or triploids.
Optimal Parameters
| CO2 | DO | °C | NH3 | NH4 | NO3 | Salinity |
| < 20 ppm | > 6 ppm | 12 – 25 | < 0.4 | < 0.4 | < 70 ppm | < 15ppt |
Although farming trout in aquaponics might not be the easiest option, we still recommend considering trout as your fish of choice! Especially if you’re living in a cooler climate! 😉
If you have any further questions regarding trout farming in aquaponics, make sure to book a consultation with us. Make sure to keep an eye out for our other Meet the Fish blog posts on our blog!
