Learn the basics of starting a fish farm

Looking to start farming fish? There's a lot to know before you begin. This guide will help you choose the right fish and teach you how to cultivate a healthy stock.

• Most fish farmers - from large-scale trout farmers to backyard hobbyists - find that buying stock from commercial hatcheries the easiest way to get fish.
• Fish are purchased as fingerlings 2 to 6 centimetres (1 to 2 1/2 inches) long. The bigger and more expensive the fingerlings, the bigger the fish you will harvest in the same period of time.
• Stocking rates vary according to fish needs and behaviour. For example, a part-vegetarian fish such as silver perch can be stocked at up to 500 fingerlings per hectare, while carnivorous species such as trout and golden perch are best stocked at half this rate or less. Freshwater crayfish are stocked at 10 to 30 per square metre depending on how large they'll be permitted to grow and how many are likely to be taken by birds.

• During the growing season, water must be added regularly to small ponds or above-ground pools to replace the water lost through evaporation. When the time comes to harvest your fish, drain out most of the water and scoop the fish up in nets. The fish can be frozen, eaten fresh, or smoked.
• Predators can be a serious problem for fish. The most troublesome in dams are cormorants (shags) and herons, which can take quite large fish. One way to minimize significant losses is to divert the attention of such predators by establishing schools of small fish and shrimp before releasing fingerlings of the larger fish. You could also copy commercial growers who use netting canopies to stop birds from preying on their fish.

• Trout are suited to deep dams in cool regions, and are often the only fish commercially available as fingerlings in those regions.
• If you enjoy summers that are long and warm, some warm-water species like silver and golden perch and tandanus catfish can be raised. They're fairly cold-tolerant but need warm water for good growth.
• The most suitable fish for smaller pools are freshwater crayfish, silver perch, catfish, and sleepy cod. Adequate aeration is essential in small pools, and it's a good idea to change part of the water regularly in hot weather.

Thought it may seem daunting, it's easier than it sounds to start your own fish farm. Follow these rules and you'll be teeming with healthy aquatic friends in no time.