Arctic char

Water parameters

Minimum tank: 500 L per individual at harvest size.

Feed and growth

Feed protein

45% target

Daily feed (warm)

1.20% of body weight

Daily feed (cool)

0.70% of body weight

Max density

60 g per litre

A 1200 g adult eats about 14.4 g of feed per day at optimum. 10 fish at adult size: ~144 g daily.

Legality

Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.

Unlisted jurisdictions default to "check local regulations".

Origin and habitat

Salvelinus alpinus lives in cold fresh water around the circumpolar Arctic and subarctic: Iceland, Scandinavia, northern Russia, northern Canada, Alaska, and a scattering of cold lakes in Britain and the Alps. It is the most northerly freshwater fish known, holding out in lakes inside the Arctic Circle where almost nothing else survives. The species sits in the salmon family alongside its close relatives the brook and lake trout, all in the genus Salvelinus. Arctic char is known for its plasticity: dwarf, normal, and large-bodied forms often share a single lake. Flesh runs from pale pink to deep red depending on how much carotenoid the diet supplies, with a clean, mild taste and high omega-3 content that drives its premium market position. Farming has grown steadily, with Iceland the long-standing world leader since the early 1990s, producing on the order of 5,000 tonnes a year out of a global farmed total near 7,600 tonnes; Canada and Scandinavia account for much of the rest. Char suits cold-water culture because it handles low temperatures better than rainbow trout, shoals rather than fights at high stocking density, and yields a high-value product.

Climate and outdoor ponds

Climate

cold-water (cool water required, dies in heat)

USDA zones

1–6 (winter low around -51°C or warmer)

Heating needed

no

Cooling needed

yes, if summer water exceeds upper tolerance

Care notes

A cold-water option for aquaponics running at 8–14°C, below the comfort band of rainbow trout, which makes char the strongest candidate for northern systems where even trout would need summer cooling. Growth is steady on a high-protein salmonid pellet of roughly 42 to 45 percent protein, with feed conversion around 1.1 to 1.4 in well-run systems, close to trout. Commercial fish are usually grown to a market weight of one to one and a half kilograms and harvested before sexual maturity, since maturing fish lose flesh quality; smaller backyard systems often aim for 300–500 g. The real edge over trout is density tolerance: as crowding rises, char shift from territorial squabbling to schooling, so farms stock them around 50 to 60 g/L with little of the fin damage and size spread seen in crowded trout. They need cold, very clean, well-oxygenated water: keep dissolved oxygen high, near saturation and comfortably above 6 to 7 mg/L, and hold total ammonia under about 1 mg/L. Fingerlings are harder to find than trout in most areas, so it is worth contacting university aquaculture extension programs or specialty cold-water hatcheries. Char is legal to raise in most places without special permits, though some jurisdictions require them, and it sells at a premium over trout.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else