Liming fish ponds

Excerpt

PROBLEMS with acid-base relationships in fish ponds can often be solved by liming, which is not a form of fertilization (8) but a remedial procedure to improve conditions for fish production.

Fish will not survive in ponds with water having a pH below 4. Where pH is between 4 and 5.5, fish will survive, but they will not grow and reproduce at normal rates (24). In many ponds with slightly acidic waters (pH 5.5-7) and acidic muds (pH 4-5.5), fish will grow and reproduce, but attempts to increase fish production by inorganic fertilization are seldom very effective (25). The diminished response to fertilization apparently results from insufficient carbon in the alkalinity system to support high rates of phytoplankton photosynthesis and rapid adsorption of phosphate in fertilizers by muds (4).

Liming materials

Common liming materials include agricultural limestone, calcium hydroxide, calcium oxide, basic slag, and liquid lime. Liquid lime, an aqueous suspension of finely pulverized agricultural limestone, reacts quickly with acidity. Because liquid lime is about 50 percent water, application rates are usually twice those of ordinary agricultural limestone.

The term “neutralizing value” refers to the relative abilities of liming materials to neutralize …