It is desirable to provide cultured fish with conditions that are
within their favoured range for optimum growth and production.
However, local environmental conditions may make a pond
unfavourable or completely unsuitable for fish culture. Problems
that are frequently encountered include soft acidic waters, low
natural productivity, high clay turbidity, oxygen depletion and
acid sulfate soils. In such circumstances it is desirable to adjust
the water chemistry of a pond in order to bring it back into the
favoured range of the culture species.
Lime, gypsum, alum and potassium permanganate are all
chemicals frequently used in aquaculture to regulate water quality
and the conditions described above. The usefulness of these
chemicals in water quality management for fish culture is
reviewed below.