Tilapia Aquaponics: Guide to growing the most Popular Aquaponics Fish

Last Updated on November 1, 2018

Tilapia is the second most cultured fish after carp and is the most popular fish in Aquaponics systems. This fish species is also considered as the oldest farmed fish & most widely grown (at least 85 countries) on earth. Tilapia are very hardy and by far the preferred species for the tropical and sub-tropical climates.

Their disease tolerance, large size, easy and rapid breeding, fast growth, omnivorous diet, tolerance to poor water conditions, and palatability makes them an ideal species for aquaponics beginners. Plant absorb the fish waste as nutrients and the clean water is returned to the fish tank.

Aquaponics fish species

The near hundred species of cichlid are more commonly known as tilapia. Tilapia traces its origins back to the Nile River Basin in ancient Egypt. Their habitat is shallow streams, ponds, rivers, and lakes. They can live over 10 years and reach a weight of over 10 pounds. Some species can reach maturity at less than a quarter of a pound depending on environmental conditions.

Name:Nile tilapia
Scientific Name:Oreochromis niloticus
Family:Cichlid
Optimal water temperature:27–30°C (80-86°F)
Vital temperature range:15–35°C (60-95°F)
Dissolved Oxygen:3-10 mg/l
pH:7.0 - 8.0
Unionized Ammonia:< 0.04 mg/l
Nitrite:< 0.8 mg/l
Hardness:50-350 mg/l
Diet:Omnivore: requires only 26-32% protein
Growth Rate:600 grams in 6–8 months

Tilapia Benefits

Following benefits makes them one of the best candidates to use in aquaponics. 

  • Adapt very well to tanks
  • Can be “crowed” in very high stocking densities (3/4 lb/gallon) within the fish-tank part of the system
  • Tilapia have a very efficient feed conversion ratio (1.3-1.8 lbs feed/lb fish)
  • Good dress out percentage (86% with head, 66% without head, and 33% fillet)
  • They adapt to their environment and are able to withstand less than ideal water conditions.
  • Tilapia grow fast and can reach from fingerling size (50 g) to maturity (600 g) in about 6-9 months.
  • They’re interesting to watch in the tank due to their rapid and frequent breeding.
  • Tilapia culture is also profitable on small-scale outdoor ponds. (variables include market price, feed costs, survival rates, technical ability, and geographic location)
  • Market acceptability & recognition and low production costs (Ponds: 51-60¢/lb, Tanks: $1.51-1.79/lb).

Water quality and temperature

Although tilapia is considered a freshwater species, it can live in brackish conditions. They are so tolerant of poor water quality conditions that they are often farmed in facilities where other fish would just die. They are a great choice for beginner aquaponics because they handle a wide range of tank conditions from temperature, pH, nutrient, oxygen levels and more.

Tilapia can briefly tolerate water temperatures extremes of 14 and 36 °C but they stop feeding or growing below 17 °C, and die below 12 °C. The ideal range to ensures good growth rates is 27–30 °C.

They are resistant to many pathogens and parasites and handling stress. However, for optimal growth and health this species, like most others, prefer DO >6ppm; pH>6; and low ammonia and nitrite levels.

Uses

Tilapia ranks fourth on National Fisheries Institute’s top list of the most consumed fish and seafood in the United States. During 2010, the average consumption of tilapia was nearly 1.5 pounds per person because they are a good source of protein. Their mild flavor makes them adaptable to many culinary styles.

They are produced in outdoor ponds as well as indoor systems for sale as live food fish to the restaurant and supermarket trade. These artisanal and commercially cultured fish is also becoming increasingly popular in many European countries.

Feed

Tilapia are omnivores and will eat just about anything from microscopic organisms through their gills, (they literally “filter” them out of the water), to algae, weeds, vegetable scraps, bugs, worms, tadpoles, etc. They also eat many alternative feeds like duckweed, Azolla spp., Moringa Olifera and other high-protein plants which makes them important in aquaculture. During breeding, they eat their own young juvenile, therefore, they need to be separated by size.

You can feed Purina line of Tilapia food called Aquamax Catfish and Tilapia. They do not have high protein requirements. Any regular pellet pond fish food that is high in vegetable protein is alright to use. Some people even feed them cat food (Iams kitten dry food is best), if nothing else is available.

Spawn

It is easy to breed tilapia in small-scale and medium-scale aquaponic systems. Healthy broodstock fish are hand-selected for breeding and are not usually harvested. The optimal ratio i.e. 2 males paired with 6–10 females encourages the spawning. Females may spawn every seventeen days, especially when water is warm, algae-filled and shaded, well oxygenated (>8.0 ppm), and in a calm environment.

Tilapia are mouthbrooders and hold their eggs in the mouths. During this time, the mother stops eating and should be separated from the male. Two smaller separate fish tanks can then be used to house the broodstock and juveniles. Mother will release fry when they start free-swimming after yolk sac disappears.

Fry are kept in a separate tank to avoid the larger fingerlings cannibalize them. The eggs and resulting fry are maintained at a temperature of 80°F to 84°F and pH of 7.5 to 7.8. You can also use small aquaponics tanks to maintain the water quality and temperature.

Here is a video of Tilapia mother releasing fry out of her mouth.

Some farms only use male fish because they grow larger and faster, do not divert energy in developing ovaries or stop feeding when spawning eggs as females do.

Sexually mature males and females in the same tank can drive competition for food because of continual fry production. Hormone treatment or hand sexing of fingerlings can yield monosex male tilapia. Testosterone-enriched feed increases the hormone levels in the blood and reverses the sex in female fry during their first three weeks of life. This is an efficient way to stock same-size male tilapia in ponds to avoid any problems of spawning and stunted growth by feed competition from the newer fry.

Regulations

There are many regulations on importing, exporting, and keeping tilapia in many states throughout the world.

The adaptable and productive tilapia can easily turn into a problematic invasive species. Tilapia production in outside facilities is strictly regulated to avoid unwanted introductions and environmental damage to native fresh-water systems, particularly to sport-fishing resources.

So it is important to prevent escapes and adhere to local regulations. So check the regulations with your state fishery department before ordering.

They are banned throughout Australia (except WA) due to their ability to overtake local waterways.

Challenges

Tilapia require warm water and may not be appropriate for winter seasons unless you have a good fish tank heater to heat the water. In temperate climates, you can grow tilapias during the warmest seasons (they are fast growing!) and switch to carp or trout during the winter. For cold areas, you rather should consider choosing a different aquaponics fish species that will grow well in your temperature range.

Their rapid breeding needs to be controlled for various reasons. They can quickly fill a small system with schools of young fish, spread juveniles to the whole system and disrupt the operations of settling tanks or nibble roots of floating raft systems. Male tilapia are usually kept because the females stop eating during breeding which is not good aquaponic plant production. They also need to be stocked at high densities because males are territorial and aggressive in low densities. Hence, You will need to have separate tanks for the female, male, breeding and juvenile.

Some people complain of off-taste of Tilapia. They taste great when they grow in a clean and well managed aquaponic system with adequate dissolved oxygen and are fed a high-quality feed.

Tilapia is also a declared pest in many areas. Watch for your local wildlife regulations!

 

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