Coarse organic materials, such as manure, sewage sludge,
hay, bran and oil seed meals, are usually suspended in the
water column in mesh bags. Cheese cloth, burlap, muslin,
nylon or other relatively loose weave fabrics may be used.
Nylon and other synthetic fabrics, however, do not deteriorate
in water as do cotton or burlap. For smaller culture
containers, nylon stockings work well for this purpose, are
inexpensive and readily available. The use of a bag prevents