How Fast do Trouts Grow in Aquaponics

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Trout is one of the few fish that humans have domesticated. When we say domesticate, we mean that we will raise the fish for a few generations and select those that are showing the best behavior and the best growth for reproduction.

Trouts can grow upto 40cm in about nine months, which is significantly fast compared to other varieties of fishes. 

So Have You Made Up Your Mind About Starting Aquaponics?

As you may be aware, Aquaponics is a closed-loop system of Hydroponics and aquaculture.

The fish and the plants have a symbiotic relationship. Like any other farming method, you have to make many crucial decisions when getting started with Aquaponics.

One of these is choosing which fish to use. When it comes to fishes, trouts are among the most popular choices, but some say they grow very slowly, potentially a downside.

But is it true? If yes, They then how can you ensure their proper growth? The answers to all of these questions are given below. 

Rainbow Trout at a Glance 

Trout, like salmon, are carnivorous cold-water fish because of their wide range of temperatures. They are appropriate for both outdoor and indoor aviaries.

Trout enjoy colder water and prosper in temperatures between 56 and 68 degrees Fahrenheit, making them compatible with a cooler climate.

Trout grow steadily in the wild, reaching a weight of about one pound after four years. Trouts are an excellent option for Aquaponics. 

Types of Trouts

There are three different types of trouts:


It is common near mountain slopes and has specks all over it.


They are also found in cold streams and have much better adaptability with temperature. You can identify them with their pink stripes and black spots over the back.


They come in shades of orange, red, and black. As the name suggests, they are brown and have originated from Europe.   

What Makes Trouts Suitable for Agriculture? 

1. Fast Growth 

A fish can reach the plate size in nine months. Trouts may grow up to 40cms in 9 months, whereas a pan-sized trout takes almost a year to grow.

If you compare it to silver perch, silver perch takes three to four years to reach the same size. When we say plate size, it’s 250 grams or 350 grams, so it’s still a small fish, but you can reach this size in nine months while many fish take way longer.

Since their rate is considerably faster as compared to other fish, you can start the new cycle earlier than expected.

2. Excellent Fish Quality 

The second reason why many people are growing trout is that they develop a fascinating aroma, an exquisite taste, and flesh of very high quality. So if you look at freshwater fish, trout is among the best quality eating fish.

When you grow trouts in Aquaponics, most of the time, the flesh of the fish is very tasty, and the color of the fish or the color of the flesh is white.

If you feed the fish with classic fish food, the meat will be more white.

The color of the flesh depends on the type of food you give to your fish. If you look at fish from aquaculture, most of the time, the fish farmers are trying to get red trout, which is not entirely red but a bit orange, or the specific pink-orange color, because that’s what the customer wants.

3. High Oxygen Requirements 

In terms of requirements, trouts need a certain level of oxygen. If you compare it to all the fish such as tilapia, carps, catfish, and other fish types famous in Aquaponics, trouts need a bit more oxygen than the other fish.

In aquaculture, the oxygen level is maintained above seven milligrams of oxygen per liter of water. 

In Aquaponics, a nice aerator or a little air pump is put with an air stone inside the fish tank, fulfilling the fish’s needs. So you don’t need any specific equipment but just be aware that trouts don’t accept a meager quantity of oxygen, such as other fish.

That’s a particular requirement that trouts have.

4. Temperature

Another requirement that trouts have is the temperature. Trouts are cold-water fish. So they are adapted to colder countries such as Europe, North America, and those countries where the water never reaches a temperature above 25 degrees.

Trouts with a temperature above 23 degrees start to struggle, and it gets hard for them to stay alive for long. So, what we have to do in Aquaponics is to keep trouts in conditions where the water is below 23 degrees.

At 18 degrees, you get an outstanding growth; 18 to 20 degrees is okay, and after that, they start to struggle.

If you want to put them in the best conditions, try to maintain your water temperature between 16 and 18 degrees, and they’re going to grow perfectly.

5. Good Water Quality

In terms of water quality, trouts are a bit sensitive. Trouts need to have good water quality and good filtration. So you need to make sure that you don’t have too much ammonia and too many nitrates in your water.

Suppose you see that your water concentration increases in terms of ammonia and nitrite, renew the water, and decrease the quantity of fish. It’s always because you got too many fish for the capacity of your system.

So you can add more filtration, more biological filtration, or you can simply decrease the quantity of fish.

Trout Care 

If there is a change in the water quality that the trouts dwell in, they can get various diseases. You should keep monitoring their color and behavior.

Regular water tests should also be conducted to keep tabs. Look out for these symptoms if you sense anything odd :

  • Eyes that are cloudy or swollen
  • The gills are moving quickly
  • Stomach that is deformed or hollow
  • Fins that are opaque, clamped, or frayed
  • Wounds, fungus development, cloudy white/grey patches or spots, or skin color changes
  • Abnormal swimming habits

Factors like fish stress, not getting a proper diet, and not getting along with other fishes can also cause problems. 

Some Tips for Avoiding Fish Diseases

  1. Keep the new fish separated from others in a separate tank for two weeks before putting them with others. 
  2. Give them a balanced diet, and make sure you do not leave the food out for too long. 
  3. Make sure your system has enough aeration, acceptable pH levels. Ammonia and nitrate levels should also be in accordance with your fish. 
  4. Avoid opening the lid to see the fish too frequently.
  5. Make sure that the dissolved oxygen limit in your tank is 5ppm or higher. Overstocking of fish can lead to low levels of DO.
  6. The fish tank should not be poorly lit as it may trigger stress in fish. 

To conclude, trouts grow relatively quicker than other fish, which will help you increase your yield.

It is low maintenance and is also widely used throughout the world, which means that its food is available easily.

Happy gardening! 

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