Fish (Aquaculture)



There are a great selection of aquatic organisms that can be introduced to an aquaponics system, including fish, shellfish, eels and other aquaticulture. Some are great to eat, whilst others make fabulous focal points within a room, and can be relaxing to watch. For whatever reason you chose your fish, please make certain you’re in a position to care for them correctly and that you can see them.

“Animal welfare is at the heart of our business. We have taken time to design and replicate naturalistic habitats for our aquaculture. Although aquaponics can be used to produce vast quantities of produce, we keep low stocking densities (an equivalent to free range) to ensure the health of all our animals remains at it’s optimum.”

 -Visit our Fish Care section to see our tips on looking after fish.



trout fingerling



Rainbow Trout/ Golden Rainbow Trout – Oncorhynchus mykiss.

Brook Trout – Salvelinus fontinalis.

Lake Trout – Salvelinus namaycush

Brown Trout  – Salmo trutta


Trout are an edible fish closely related to Salmon and Charr. They require an intermediate level of experience to keep. Some live exclusively in freshwater, but some spend time out at sea, before returning to freshwater to spawn.  Their spawn are reffered to as troutlet or fry. 

Temp: 2-16°C

pH: 7.0 – 8.0 (will not reproduce if conditions are acidic)

Size: 50-75cm and 1-2kg in captivity, but in the wild adults can grow to  4 feet and 3.6kg

Diet: Other fish (up to 1/3 their own length), shrimp, mealworms, soft bodied aquatic invertebrates such as dragonflies and other insects or zooplankton such as algae. Trout pellet is available from fishing shops, but may not be organic.



Sturgeon  Acipenseridae family (which appeared on the fossil record 200 million years ago!) This comprises of twenty-five or so species; of which most are  now facing extinction due to habitat destruction, overfishing and pollution. Here are species you are likely to find for sale in the UK:


Siberian/ Long nose Sturgeon – Acipenser baerii

Stellate Sturgeon – Acipenser stellatus

Sterlet Sturgeon – Acipenser ruthenus

Diamond/Gold spot Sturgeon – Acipenser gueldenstaedtii

When able, they are relatively long lived; only reaching maturity to reproduce at a similar age to us at 18 to 20 years old – unfortunately for them, their roe is highly prized as caviar. This makes them the most valuable harvested fish. In the UK sturgeons are classified as a “Royal fish” and upon being caught are property of the monarch, so fish must be bought from reputable dealers.

Temp: Sturgeon less than 4″ require 10-15°C when bigger than 10cm, they enjoy around 20°C but can tolerate up to 22°C over this, they will stop feeding.

pH: 7.0 – 9.0

Size: Although in the wild they can reach 7-12 feet, they should only grow to around 1m in captivity.

Diet: They do not have the right enzymes in their stomachs to digest most plant proteins or carbohydrates – although they will try to eat foods made of soya or wheat (e.g. trout food). Instead, they require a high fishmeal/ shrimp content in their food.


Perch Percidae family. The greenish European species Perca fluviatilis have dark stripes and red/orange tips on the fins. Other species used in aquaponics include Silver and Jade.

Temp: 17 – 25°C

pH: Varies between species. Most grow best between 6.5 – 8.0  

Size: Average is 10-25cm. The British record is 60cm long and 2.8kg

Diet: Small fish such as minows, and sometimes other perch, zooplankton, insect larvae.


Carp – Cyprinus caprio

Temp: Can tolerate 2 – 35°C but prefer 23-30°C. Spawning begins at 17°C.

pH: 6.5 – 9.0

Size: up to 120cm, average is 40-80cm

Diet: Omnivores, will eat plants, insects, zooplankton etc. Carp pellets are available from fishing shops, but may not be organic.


Koi – Cyprinus caprio subspecies. haematopterus




Koi are a type of carp, and have been kept for their colours and beauty for centuries. In Japanese the word “koi” is also a homophone for a word  meaning “love”, this is why Koi are given as symbols of love or friendship in Japan.


Temp: Koi immune systems work best over temperatures of 12.5 ° Celcius, but Koi tend to prefer temperatures between 20-25 °C . However, they have been known to tolerate temperatures at the extremes of 2 ° C – 30 ° C

pH: Ideally require pH 7.5, but will do still do well between pH 6.5 – 8.2.

Size: Pet shop: 12-15″ long , Japanese: 22-26″ and Jumbos will grow up to 1m 

Diet: During Summer, Koi require a higher protein diet, in winter this can change to a more wheat-based diet



Goldfish – Carassius auratus

Can be the ideal starter fish, especially for families.

Temp: To replicate the natural environment, goldfish should be kept at 10-12° C over winter and gradually warmed up to 20-23° C in summer. This will encourage them to breed as they would in the wild. 

pH: Tolerate slow changes in pH 6.0 – 8.0

Size: healthy goldfish should grow up to 10″

Diet: Flake food, worms from your vermiponics, goldfish food will be supplied at most pet shops.



To catch and handle crayfish you need a licence from the Environment agency. Redclaw crayfish are the only crayfish allowed to be kept in aquariums in England and Wales.

However, the only crayfish native to the UK are White-clawed crayfish Austropotamobius pallipes.  Unfortunately, due to the introduction of invasive non-native species such as the Redclaw crayfish, a carrier of crayfish plague, the  White-claw populations are in decline.

Did you know?  White-claw crayfish mothers carry their eggs for 9 months until they hatch, and can live up to 12 years. They breed around August through to early winter, and usually hatch May-July

Temp: Varied between species, usually 18-25° C

pH: Hard water, with a slightly alkaline pH, 7.5 – 8.5, is best. (soft or low pH water could cause calcium deficiencies) 

Size: Up to 12cm long

Diet: Omnivorous. Will eat lettuce, courgette, shelled peas, and aquarium plants, as well as other invertebrates, blood worms, sinking pellets, pieces of dead fish such as shrimp, salmon etc. Note: Crayfish stash their food by burying or hiding it, so check before feeding them, as this could cause an ammonia spike.



Note: These fish are often costlier to run in the UK, as their water needs to be heated.

Tilapia (various species)

first tilapia

One of the most commonly used fish in aquaponics, due to their rapid growth rate (reaching a harvestable size at just 6 months – but will live for 10 years) as well as their ability to cope well with pH swings which makes them ideal for beginners. However, they do not make good community-tank fish.

Nile Tilapia are also called “St.Peter’s fish” as they were the fish used to “feed the masses” according to the Bible – this wouldn’t be surprising given their rapid growth-rate.

Tilapia are low in saturated fat, calories, carbohydrates and sodium, and are a good protein source. They also contain Vitamin B12.

Temp: Between 22-31 °C. If temperatures reach below 17 °C they may stop feeding (and producing the right amount of ammonia for your plants) If allowed to drop below 12 °C this can be lethal to their health.

pH: Can tolerate 5.0 – 10, but prefer 6.0 – 9.0

Size: at 6 months they will be plate sized, but can grow between 40-60cm in the wild.

Diet: Mostly vegetarian inluding algae, plants etc (this diet reduces fishing pressure on prey species)



Sleepy Cod – Oxyeleotris lineolata

One of the most desired edible fish. Males guard nests of up to 70,000 eggs until larvae hatch!

Temp: 22-27°C

pH: 6.8 – 8.0

Size: 45cm

Diet: Carnivorous. Eating other fish, worms, insects and crustaceans.


Barramundi is an Aboriginal word meaning “large-scaled river fish”, also known as ‘Giant perch’. Popular because of their rapid growth rate, some harvest at 6-8months, depending on feed, but can live to 25 years.

Temp: 25-30°C

pH: 7.0 – 8.5

Size: Can grow more than a metre!

Diet: Carnivorous. Eating other fish, worms, insects and crustaceans, have also been known to eat crocodiles! (not suitable for community tanks)


Giant Prawns – Macrobrachium rosenbergii

Scampi are a popular choice, grown as they are less expensive to feed on a large scale than shrimp.

Temp:  28-31°C

pH: 7.0 – 8.5

Size: Female 25cm, male 32cm

Diet: Omnivorous. Zooplankton, worms, plants


Freshwater Clams 

A filter feeder that actually improves your water quality.

Golden clam – Corbicula fluminea 

Temp: 18-28°C

pH:6.5 – 8.0

Size: Born just 1mm long, it takes them 4 years to reach maturity (1cm long) they can then grow to 5cm (1-2″ )

Diet: Filter feeders, eating detritus, bacteria, algae, and other small particles, adding an extra level of filtration to your set up.



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