Cage Culture -- Tanks

Cage Culture

Tanks

Tank size is another important consideration. Atlantic salmon, which work best for farming, grow well with high water flow and dim light. In Norway and Scotland, a standard tank is around 3-4 meters in diameter, at least 1 meter deep, and typically made of reinforced fiberglass. Stocking density in these is 10-30 kilograms to every cubic meter. These tanks are for yearling smolts. For 2-year old smolts, tanks are 5-7 meters in diameter and stocked with 15-20 kilograms per cubic meter. For larger and older smolts, freshwater tanks are used, since these are cheaper to construct and maintain.

Most tanks are circular in shape. This shape provides the best flow over a greater water mass. Circular tanks are also easier to clean, another useful consideration. The volume of the tank should be changed at least every hour, or possibly twice an hour.

The speed of the flow is determined by the swimming behavior of the fish and the need to clean the bottom. In a circular tank, higher velocities can be induced by rotational movement.