How Long Do Aquaponics Fish Take To Grow?

Aquaponics fish can take anywhere from a few weeks to several months to grow, depending on the species. In a few situations, you may even be able to harvest them before they reach full size. So, if you’re thinking about starting an aquaponics system at home, you must know how long it will take for your fish to grow. While the answer can vary depending on several factors, we can give you some general guidelines to help you out. 

Primarily, two main things help fish thrive well in an aquaponics system: light (sunlight or artificial light) and space, besides nutrients, feeding schedule, temperature control, maintenance, and more. The latter vary based on the type of fish you choose to raise through aquaponics farming. 

Let’s start by understanding the role of sunlight.

Does Aquaponics Need Sunlight?

Well, fish can exist in an aquaponics system without light. However, their growth depends on both dark periods for their survival and the amount of natural sunlight they receive each day to function properly. Also, without enough light, your fish can become weak and ill. 

The good news is that artificial light can help improve egg production and health in the absence of sunlight, especially when paired with modern technology. The latter has created innovative solutions to give you better results than ever before. 

Aquaponic Sunlight

How does light affect fish growth?

There’s a lot of talk about the effect light has on aquaponics fish, but it’s still an opinionated topic in scientific circles. Some say that too much can be harmful, while others disagree and claim there isn’t enough research to support their claims.

Most argue that you should avoid sunlight on your aquaponics fish tank because it causes algae growth. Yes, this is true, however, you must also allow your plants to soak in sunlight every day or at least some amount of artificial light each day.

What do aquaponics fish do with the sunlight?

Generally speaking, aquaponics fish require light to locate their food. It serves other essential functions as well. A study reports that aquatic animals are naturally sensitive to light. The way a fish’s environment is set can have an impact on its overall health and productivity. 

To elaborate, the intensity, spectrum, photoperiod received each play their role in determining the kind of plants or algae growth within the water while also influencing certain behaviours like schooling patterns, among other things. 

But, what if enough natural sunlight is not available?

In such a case, the suitable types of lights can make a world of difference; they also help regulate the temperature in your aquaponics system. Moreover, they’re also an excellent alternative for heaters. For instance, although it is a warm water fish, one can grow Tilapia in colder regions.

So what types of artificial lights are good for fish growth.

Which lights are good for aquaponics fish growth (if not sunlight)?

Options are many, but the right ones are as under:


If you want to give your fish the best chance of survival, we recommend getting an LED light. This type will last longer and provide just enough warmth for any size tank- even big ones.

Aquaponics Led

Incandescent and Fluorescent Light

You may use incandescent and fluorescent light bulbs. But note that they have limited features, which means it’s tough to adjust their intensity or heat level. These lights can cause abnormal biological responses in some aquaponics fish, so use them with extra caution.

Does light distribution influences aquaponics fish growth?

Certain factors can affect water temperature. One of the most significant is light distribution, as it could naturally change which portions get warmer or colder due to how your tank’s glass reflects natural sunlight throughout its surface area.

How much sunlight is sufficient for fish growth?

If you’re trying to grow fish in an aquaponics system, the lighting schedule must be tailored for their needs. Note that most common freshwater and saltwater species would benefit from around 12 hours of light per day.

For natural light

The critical thing to remember if you live in a tropical region is plenty of natural light. However, too much can put your fish in danger so make sure they’re surrounded by shade or covered with an extra tent. This will protect them from extreme temperatures and excessive algae growth, which could quickly kill off their habitat, if left unchecked.

How Much Land Do You Need For Aquaponics?

The best method to figure out how much land you need for aquaponics is by thinking about what kind of system will work with your needs. When deciding how big of an aquaponics system to get, a few factors should be considered.

The number and type of fish you want and what plants will grow in your system determine the size needed for optimal performance.

Is there a correlation between the size of aquaponics fish and the space required for an aquaponics system? 

The size of your fish tank and grow beds matter in an aquaponics system. In this, both must be proportionate to one another. There will be no adequate filtration for either aquaponics fish or the plants if they’re not.

Fish Tank

The size of your fish tank dictates how many types and sizes can be grown in an aquaponics system. If you plan to build a small desktop unit using tanks for aquatic life, it’s only possible to keep ones that live comfortably within the dimensions – not too big but also without any room.

If you wish to grow larger, edible fish, the right tank is a 50 gallon (189 liters) water depth at least 18 inches of space for them. Your aquaponics fish must have enough room to not stress or bother their surroundings too much during the growth period.

Besides, two more factors are responsible for how quick or slow your aquaponics fish will grow in the aquaponics tank.

Aquaponics Fish Tank

Rearing fish

When you want to rear more fish, the ratio can be increased. A pound of fresh or frozen Tilapia per 3 gallons is ideal for a small tank. It will allow you to enjoy their delicious fish without worrying about running out of space!

Ornamental fish

1 pound worth of goldfish would require about 5 gallons for living quarters. The same amount of water can house more fish.

Size of the Grow Bed

That matters too! While deciding the size of your grow bed, you need to consider how much space is available for the aquaponics system. The recommended ratio for this type of setup would be 1:1 – implying that there should always be six gallons (22 litres) per every foot cubed when determining the total volume needed by both plants and fish alike.

The general rule of thumb for fish tank size and the grow bed volume is 2:1, but you should reduce the stocking density in your aquaponic tank accordingly. This approach allows for better filtration due to higher plant productivity per square foot on aquaponic plants.

Aquaponic fish you can grow in an aquaponics system

To help you choose, here are a few for your consideration.


Tilapia is an excellent choice for beginners because it requires little maintenance. They also have an easy-to-keep temperament, but they can become aggressive when breeding, so if you plan on having more than one fish in your tank, be prepared. It grows faster than many others and can grow up to 2 pounds in only 7 months.

Jade Perch

The Jade Perch is a native of Australia. They’re high on Omega-3 oils and are perfect to eat at one or two pounds. It grows quite rapidly to the size of one pound or 500 grams. You’ll get this in 12-15 months when growing them in an Aquaponics system. In the recirculation system, they increase to 800 grams in seven months.


Goldfish is a popular choice for aquaponics systems. They do well in most environments, making them suitable. Goldfish grow fast! In 8 weeks, they are approximately 1 inch long. By 6 months, they are full-grown and may continue to grow more.


When raising them indoors, the average size needed by catfish would be around 300 gallons since this type tends toward larger sizes than other types. The average time for a catfish to fully mature is two years, but it can be as short or long-lasting depending on their age when they’re first bred.

Catfish Aquaponics

Other Factors Responsible for Aquaponics Fish Growth

The growth rates of individuals can vary depending on where they live.


Aquaponics fish slow down as they grow older because there is not enough nutrient material to support growth. In fact, at sexual maturity, when this occurs, it can be difficult for fish cells to contain large amounts of energy from food to produce eggs or sperm.


The growth of an aquaponics fish is affected by the temperature. In summer, they grow fast, but in winter, it’s slower because there’s less light and more water that reaches the freezing point.

Summing up

If you consider starting an aquaponics system, your aquaponics fish growth rates will help you plan your production schedule. The numbers mentioned above are to help you decide the aquaponics fish type you can raise. Hope it helps.

Aquaponics Plant

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