Atlantic salmon

Water parameters

Minimum tank: 2000 L per individual at harvest size.

Feed and growth

Feed protein

45% target

Daily feed (warm)

1.20% of body weight

Daily feed (cool)

0.80% of body weight

Max density

60 g per litre

A 5000 g adult eats about 60.0 g of feed per day at optimum. 10 fish at adult size: ~600 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

Salmo salar is native to rivers draining into the North Atlantic, from Portugal and Spain north to Norway and Iceland in Europe, and from Connecticut north to Labrador in North America. In the wild it is anadromous: fish spawn in fresh water, the young spend one to three years in the river as parr, then smoltify and move out to sea, returning to their home river to spawn after one to three years in the ocean. It is the most commercially important salmonid in the world. Farmed output, almost all from marine net pens, has climbed from a few tens of thousands of tonnes in the early 1990s to well over two million tonnes, about 2.4 million tonnes in 2018 and higher since, led by Norway with more than half of supply and Chile with roughly a quarter, followed by Scotland, Canada, and Tasmania. Wild stocks tell a different story: numbers have dropped sharply since the 1970s, and in a 2023 reassessment the IUCN moved the species to Near Threatened globally. The freshwater smolt-rearing phase, and the fast-growing shift toward full-cycle land-based recirculating systems, are what make Atlantic salmon relevant to freshwater and aquaponics-style production.

Climate and outdoor ponds

Climate

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

USDA zones

3–7 (winter low around -40°C or warmer)

Heating needed

no

Cooling needed

yes, if summer water exceeds upper tolerance

Care notes

Not a typical home aquaponics species due to the complexity and scale required, but included because land-based Atlantic salmon RAS facilities represent a fast-growing aquaculture sector and several commercial operations are exploring integration of plant production with salmon waste streams. The species requires cold water (8–14°C for optimal growth), high dissolved oxygen (above 7 mg/L), and pristine water quality (ammonia below 0.5 mg/L, CO2 below 15 mg/L). Growth in freshwater RAS is moderate: smolts reach 80–150 g in 12-18 months, and post-smolts can be grown to 3–5 kg harvest size entirely in freshwater at 12–14°C over 24-36 months. FCR is excellent at 1.1-1.3 on high-quality salmon pellet (40-48% protein, 20-30% fat). Stocking density in well-managed RAS: 40-80 g/L with supplemental oxygen. Disease management is demanding: ISA, BKD, sea lice (marine), and Saprolegnia require biosecurity protocols. Smolts are available from commercial hatcheries but in quantities suited to large operations. The economics require volume. For home aquaponics, rainbow trout or arctic char are far more practical cold-water alternatives.

Further reading

• The history of aquaponics: chinampas to backyard IBC totes