Cages should be constructed from materials that are durable, light-weight and inexpensive, such as galvanized and plastic coated welded wire mesh, plastic netting and nylon netting. Welded wire mesh is durable, rigid, more resistant to biological fouling, and easier to clean than flexible material, but is relatively heavy and cumbersome. Plastic netting is durable, semi-rigid, lightweight and less expensive than wire mesh. Cages made of nylon netting are not subject to the size constraints imposed by other construction materials. Nylon mesh is inexpensive, moderately durable, lightweight and easy to handle.
Nylon is susceptible to damage from predators such as turtles, otters, alligators and crabs.
An additional cage of larger mesh and stronger twine may be needed around nylon cages. These mesh sizes provide adequate open space for good water circulation through the cage to renew the oxygen supply and remove waste. The use of large mesh size requires a larger fingerling size to prevent gill entanglement or escape. Larger mesh size facilitates the entry of wild fish into the cage. These fish will grow too large to swim out of the cage, but they do not grow large enough to reach marketable size, thereby representing a waste of feed.