Fish Farm with Cages!

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

AND NOW . . . THE CAGE

Once you've gotten access to a body of water and are confident that you'll be able to line up a supply of fish, it's time to build your cage. (You could, of course, buy a fish box, but commercial cages often cost three to five times more than homemade units.) Rectangular cages seem to work best. And while we once raised bullheads in 24-cubic-foot enclosures at New Alchemy—and commercial growers often use cages of as large as 1,000 cubic feet—home growers planning to manage one to six boxes will probably do well with a 3' X 3' X 6' (or 54-cubic-foot) structure. (See the illustration that accompanies this article.)

Although you can make the cage walls out of almost any sort of mesh material, I prefer nylon webbing, such as Du Pont Vexar, which is sold in hardware stores (and by aquaculture supply companies) and often used to keep leaves out of rain gutters. Flexible nylon mesh is easy to work with, slightly buoyant, long lived, and chemically inert. Wire, on the other hand, may be initially less expensive but it's also much heavier than nylon—so you'll need extra flotation to compensate for the added weight—and it usually has sharp ends that can injure people and fish. Worse yet, all but the bestcoated wires corrode in water. I've heard many sad but true stories about bumper fish crops that fell through cage bottoms at harvest time!

Whatever material you use, though, you'll improve water circulation, reduce your cleaning labors, and save some money if you purchase the largest mesh that's capable of preventing your new baby fish from escaping. (We often used 1/2" mesh at New Alchemy.)

Your cage will need a rigid top frame made of either treated wood or aluminum tubing, and you can frame all of the underwater sides of the cage as well, if you wish. (Noncorroding nylon cable ties—available from electrical supply stores—are my personal choice for fastening the mesh to this frame.) Or you can make a "basket" cage by simply "sewing" the sides together with nylon rope or twine. Basket cages are lighter, easier to store, and less expensive to make than full-frame ones, but I've found that they take longer to construct and don't hold their shape as well.

The other three essential cage components are the flotation devices, a top, and a feeding ring. It takes one cubic foot of poly styrene foam (an ideal flotation material) to support a 50-cubic-foot full-frame, nylonweb cage. Since the polystyrene may crumble with time, though, you should enclose it in sturdy, water-resistant bags. (It must also be attached in such a way that the top of the cage sits at least four inches above the water level.)

The cage will require a hinged or removable top, because most fish prefer shade to sunlight. (This lid will also help deter theft, predation, or high-leaping escapes.) The feeding ring is simply a band of fine mesh—such as mosquito netting—that prevents floating feeds from slipping out the sides of the cage. You can stitch a length of this material around the inside of the cage at the water line ... construct a smaller floating, wood-framed feeding skirt ... or cut a feeding "well" hole in the cage's lid and trim that with the netting.

And how much will all this cost? Well, the price will naturally vary depending on where you live, but in 1979 we were able to construct a 48-cubic-foot (4' X 4' X 3) basket cage from Vexar and treated wood and fit it with a lockable plywood top, canvas-wrapped foam flotation, and an attached feeding ring ... for only $47.

RSS | Comments | E-mail | Print