Pohan Panjaitan
One of the main obstacles to develop an intensive aquaculture is the accumulation of toxic inorganic nitrogen
which should be kept very low by frequent water exchange or recycling of the water through a biofilter.
This study describes another method of removing inorganic nitrogen using heterotrophic bacteria population
of which was augmented by the addition of a carbonaceous substance, molasses, to increase the feed C:N
ratio under laboratory condition. The principal aim of study was to establish correlation C:N ratio level
with levels of ammonia, nitrite, dissolved oxygen, pH and shrimp growth in Penaeus monodon shrimp
culture with Zero Water Exchange Model (ZWEM) using molasses as carbon resource. It was found that
addition of molasses to shrimp farming with ZWEM had a role in removing ammonia and nitrite. Also,
application of molasses to laboratory tanks increased the growth and percentage weight gain of shrimps and
increased the population of heterotrophic bacteria.