Adequate supply of well-oxygenated water and inexpensive and nutritious feed. Advantages: very dense stocking, abundant supply of dissolved oxygen, easy removal of waste products, high rates of production. Disadvantages: requirement of large volumes of water, dependence on artificial feed, high initial cost, energy wastage in swimming against currents.
3. Different types of structures used in running water culture for seed rearing and growing to market size
Raceways, ponds, tunnels, troughs, vats and tanks; materials used in their construction; their shape and dimensions.
(a) Different designs - long, narrow, rectangular brick or concrete channels, circular channels and flat spirals; semi-raceways; "open" or "flow-through" systems and "closed" systems;
(b) Criteria for selection of site for location of raceways; topography, soil characteristics, erosion control and water supply;
(c) Construction; excavation and/or level building; slide slopes; construction of water control structures or weirs - materials used (concrete, wood, sheet metal, etc.); functions of water control structures (regulation of flow and depth of water, aeration, etc.); effects of shape and slope of raceways on water flow;
(d) Sources of water for raceways; determination of flow rates; methods of filtration/purification in closed systems.
5. Culture operation
Species culture in running waters; stage and size of seed used; rates of stocking in relation to flow of water, temperature and feed; feeds, rates and methods of feeding; rate of production and its relation to rate of water flow.
6. Economics of running water culture compared to pond culture and other systems of culture
Designing of raceways and other running water culture systems; experimental culture of selected species in running water systems.