Since this is a nitrogen-related
problem, the most obvious preventive
measure is to reduce or
minimize the amount of nitrogen
incorporated into the system by
reducing feeding rates. However,
in modern intensive pond or
closed system fish culture with
high densities and rapid growout,
longterm feed reduction is not
considered by most farmers as a
viable option. Luckily, although
we often cannot prevent the
occurrence of high nitrite, its
effects can be minimized or neutralized
safely and economically.
Sodium chloride (common salt,
NaCl) is used to “treat” brown
blood disease. Calcium chloride
can also be used but is typically
more expensive. The chloride portion
of salt competes with nitrite
for absorption through the gills.