Arctic char

Quick facts

Adult size

45 cm, 1200 g typical harvest weight

Days to harvest

540 to 900 days from fingerling

Lifespan (max)

up to 25 years

Diet

carnivore

Temperature class

cold-water

Difficulty

intermediate

Water parameters

Temperature range

0–18°C (optimum 12°C)

pH

6.5 to 8

Hardness

3 to 20 dGH

Minimum tank

500 L per individual at harvest size

Feed and growth

Feed protein

45% target

Daily feed (warm water)

1.20% of body weight per day

Daily feed (cool water)

0.70% of body weight per day

Max stocking density

60 g per litre of system water

A 1200g adult eats about 14.4 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 144 g of feed daily.

Legality

Aquaculture and possession rules vary by jurisdiction and change over time. This table reflects regulations as of the verified date on each row. Verify with your local fisheries or wildlife authority before stocking.

Jurisdictions not listed here default to "check local regulations". A non-listing is not a green light; rules in your specific county or municipality may apply.

Habitat and origin

Native to cold freshwater lakes and rivers across the circumpolar Arctic: Iceland, Scandinavia, northern Russia, northern Canada, Alaska, and alpine lakes in Britain and Central Europe. The species (Salvelinus alpinus) is the northernmost freshwater fish on Earth, found in lakes within the Arctic Circle where few other species survive. Closely related to brook trout and lake trout (all genus Salvelinus). Arctic char exhibits extreme phenotypic plasticity, with multiple morphs (dwarf, normal, and large forms) often coexisting in the same lake. Flesh color ranges from pink to deep red depending on diet (carotenoid content), with a mild, clean flavor and high omega-3 fatty acid content. The species is the basis of a growing aquaculture industry, particularly in Iceland (the world leader in char farming, producing over 8,000 tonnes annually), Canada, and Scandinavia. Char is valued in aquaculture because it tolerates cold water better than rainbow trout, grows well at high stocking densities with less aggression, and produces a premium product.

Climate and outdoor ponds

Climate classification

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

Outdoor pond zones (USDA)

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

Heating in a temperate climate

Not required (handles seasonal cool periods)

Cooling in a temperate climate

Required if your summer water temperatures exceed the upper tolerance

Zone bounds reflect year-round outdoor pond viability with no active heating. Anywhere outside the bounded zone, the species can still be kept in an indoor heated tank or a seasonally-managed system. Verify your specific microclimate, as a sheltered yard zone can run a half-zone warmer than the regional rating.

Care notes

A cold-water aquaponics species for systems operating at 8–14°C, colder than rainbow trout's optimal range. This makes arctic char the strongest candidate for aquaponics in northern climates where even trout would need summer cooling. Growth is moderate: 300–500 g in 18-24 months on high-quality salmonid pellet (42-45% protein). FCR is 1.1-1.4, comparable to rainbow trout. The key advantage over trout is density tolerance: char are naturally schooling fish that accept crowding better than trout, with commercial farms routinely stocking at 30-60 g/L. They're also less aggressive at feeding time, which reduces fin damage and size variation within cohorts. Dissolved oxygen must stay above 6 mg/L. Ammonia sensitivity is similar to trout; keep TAN below 1 mg/L. Water quality overall must be excellent. Fingerlings are harder to source than trout in most regions; contact university aquaculture extension programs or specialty cold-water hatcheries (several operate in the Great Lakes region and New England). Legal in most jurisdictions without special permits. The retail price ($15-25/kg) is higher than trout, reflecting the premium positioning. Arctic char is an excellent choice for aquaponics operators in cold climates who want maximum value from their cold water.

Further reading

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