How to Raise Trout in Aquaponics Systems

August 06, 2022

If you live in a colder climate and looking to raise a delicious fish that grows well in cooler water, then a trout aquaponics system is for you. Trout is a cold-water fish that is not difficult to raise because these fish species do not require complex care.

However, many newbie aquaponics growers tend to shy away from raising trout because of their unfamiliarity with the fish's growing requirements. This article will discuss everything you need to know about raising trout in your aquaponics system.

Why Raise Trout in Your Aquaponics System?

Trout has a delicious flavor and great texture and is a fast-growing freshwater fish cultivated widely in countries with colder climates. They grow into plate size faster than other fish species, which is excellent in aquaponics systems because it would mean double income from fish and plant harvest.

Trout can also tolerate a range of temperatures, which is why it is gaining popularity as one of the best fish species to raise in aquaponics systems.

What are the Different Species of Trout?

There are 14 varieties of trout fish species that exist around the world, but the most common varieties used for aquaponics systems are:

1. Rainbow Trout

Rainbow trout is the most famous trout fish specie for aquaponics systems. They can be identified through the prominent pink stripe on their side, an array of black spots, and pink or red cover over their gills. They are usually found in cold mountain streams, but trout can tolerate various temperatures.

2. Brook Trout

Also called speckled trout, the brook trout typically live in cold water streams and are native to Eastern North America in the US and Canada. They are a member of the Salmonidae family, which includes salmon and some cold-water fish species. The Brook trout can be easily distinguished from their yellow spots on an olive-green back.

3. Brown Trout

The brown trout, also called the European trout, is Native to Europe and Western Asia, but can also be found in North America. Brown trout do not necessarily come in brown color. They come in various colors, which include silver and golden, depending on where they live. They can be distinguished by the orange-red markings surrounded by silver rings and their salmon-like appearance.

What Trout Species is Best for Aquaponics?

The best trout species for aquaponics systems is the rainbow trout. This is because rainbow trout is the hardiest trout variety and requires less maintenance. These features make rainbow trout easy to grow for farming and to grow with plants in aquaponics systems.

Advantages of Growing Trout in Aquaponics Systems

Trout are low maintenance. They do not require much and can care for themselves with little help.
Trout are fast-growing fish. They can grow to about 40 cm or 15 inches in 9 months. A pan-sized trout can take about 12 -13 months to grow, which is faster than other fish species.
Trout have excellent flavor and texture. They are widely farmed for food or sale.
They can survive in a wide range of water temperatures.
They are great for aquaponics systems in a colder climate.

Disadvantages of Growing Trout in Aquaponics Systems

They are recommended for more extensive and smaller systems because they require fast flow rates.
They are limited to colder climate aquaponics systems.
Trout requires a high dissolved oxygen level of 5.5mg/L to thrive.
Trout require a large tank of at least 200 gallons.
Trouts are dominant fish species and territorial. They cannot be mixed with other fish species in the fish tank as they might kill the less dominant fish.

Growing Requirements for Trout in Aquaponics Systems

Here are the growing requirements for raising trout in aquaponics systems.

Stocking Density

For trout, it is recommended to have a stocking density of 7-10 gallons of water for every 1 lb of fully mature fish.

Tank Size

The minimum tank size requirement for trout is at least 200 gallons. This means you will need a larger fish tank if you intend to grow more trout. Overcrowding your tank might cause problems such as stunted fish growth and low dissolved oxygen level.

pH Level

Trout required a pH level range between 6.5 - 8 to thrive.

Water Temperature: Being a cold-water fish, trout thrives in a temperature range of between 56°F and 62°F (13°C - 16°C).

Fish Diet

Trout are carnivorous fish. They required a diet that consisted of 40-50% protein fish food. The fish feed must be of high quality to ensure proper growth, health, and delicious flavor of the fish when they are harvested.

Feeding

Feed the fry at least ten times a day at the start. However, the feeding frequency will decrease to two to three times a day when the fish matures. Since trout live in cooler water, they have slower metabolisms than the other fish. So make sure not to overfeed and underfeed your trout to maintain their health.

Oxygen Requirements

Trout requires higher levels of dissolved oxygen. The recommended DO level for them in the tank is 7.0 ppm.

Breeding

To breed trout, collect the milt from the male and strip the female of their eggs. Collecting milt from more than one male is recommended to ensure fertilization. Mixed the milt with the eggs and add water to the mixture to activate the sperm to begin fertilization.

Once fertilized, the eggs are then ready to transport 20 minutes after and should be done within 48 hours. Avoid direct sunlight to the embryos for them to survive.

Can Trout be Mixed With Other Breed?

Trout are dominant fish species and tend to exhibit territorial behavior. Trout can be mixed with other freshwater species such as Silver Perch as long as they are of the same size. However, do not add juveniles to the bigger fish because the big fish will only eat the smaller fish species.

Factors to Consider in Raising Trout

It will help to consider these essential factors before raising trout in your aquaponics system.

Fish Tank

Trout are large fish species and require larger fish tanks. Large tank size will give them enough space to swim and dilute water quality issues. As mentioned above, the minimum tank size requirement for trout is 200 gallons.

Trout don’t perform well in warm and stagnant water. They prefer water with a fast flow rate because this ensures that waste will not be stagnant at the bottom of the tank.

Filtration System

Monitoring the ammonia, nitrite, and nitrate levels are essential for growing trout. Trout thrives in a healthy and clean environment. So make sure to monitor the water quality of your system. An additional filtration system is recommended for raising trout to ensure the water quality in the fish tank is maintained.

Water Quality

The natural habitat for trouts is clean, cold, and well-oxygenated mountain stream water. It is important to imitate their natural habitat in the fish tank for their health. As much as possible, maintain the good water quality in the fish tank and ensure that the pH, dissolved oxygen, temperature, and other water quality parameters are within their ideal range.

Trout thrive when the water temperature is within the ideal range of 59°F and 85°F, but their growth rates will begin to decrease above 70°F. So as much as possible, keep the water temperature cooled. Spawning starts when the water temperature is at 50°F, and a female trout may produce eggs as many as 12,000.

Although trout do not like dirty water, they have a very strong tolerance to salinity, and many trout varieties can still survive in brackish water and other marine environments. The acceptable pH range for trout is between the range of 6.7 to 8.2. However, regular monitoring, filtration systems, and air pumps can help maintain good water quality.

Caring for Trout in Aquaponics Systems

Fish health and care are critical and essential to your aquaponics system's overall health and function. So understanding what your fish need is an integral part of running a successful aquaponics system because waste production slows if the fish are unhealthy, resulting in poor plant growth and harvest.

Monitoring and a regular water test are essential to the success of your system—the best time to monitor the behavior of your trout fish is during feeding.

Here are some important ways of maintaining a healthy trout in your aquaponics system:

Observe fish before and after their daily feeding and note how much feed is eaten.
Observe and take notes of the fish's behavior and appearance daily.
Understand the signs of fish stress, disease, and parasites.
Maintain a low-stress environment with consistent good water quality, specific for the fish in the system.
Use the proper stocking density and feeding rates.

Healthy Fish Behavior

A healthy trout shows the following behavior:

Extended fins and straight tails.
A graceful pattern of swimming. No lethargy.
A healthy appetite and not shying away at the presence of the feeder.
No marks, discolored blotches, streaks, or lines.
Not rubbing or scraping on the sides of the fish tank.
Sharp, clear, and shiny eyes.

Tips on How to Prevent Fish Diseases in Your System

Purchase healthy fish from a reliable and reputable fish supplier.
Quarantine new fish in a separate tank before introducing them into an established fish tank.
Feed the fish with a proper, varied, well-balanced diet.
Keep your system's water quality clean at all times and ensure that it is within the ideal levels of water quality parameters of pH, ammonia, nitrites, nitrates, and temperature.
Ensure enough aeration to keep the DO as high as possible.
Remove uneaten fish food from the tank.
Ensure that the water is from an excellent source, clean, and free of chlorine.
Make sure that the fish tank is in an excellent shaded place.
Follow the standard hygiene procedure by washing hands and using clean gear or equipment.
Treat the disease as soon as it is identified.

Conclusion

You can successfully raise trout fish in your system if you live in a cooler climate, maintain good water quality, and follow the growing requirements for trout. Thank you for reading our article. Read “The Ultimate Aquaponics Beginner's Guide” to learn more about aquaponics.