Abstract:
Integrated aquaculture-hydroponics systems were operated in closed recirculating
system without daily discharge of water or organic matter during 35 days of culture
period. During the culture period, three kinds of biofilter media (broken shells,
charcoals and gravels) were evaluated for their efficiency in relation to biofilter
efficiency (E), water quality and filter media economics. Specific growth rate (SGR)
and survival rate of hybrid tilapia ( Oreochromis sp.) as well as fresh weight ofloose
leaf lettuce (Lactuca saliva var. crispa) were investigated. The trickling filter
combined with the nutrient film technique (NFT) accomplished the biological
filtration in maintaining water quality for tilapia culture system. Results showed that
pH and total ammonia nitrogen (TAN) concentration of rearing water differ
significantly (P < 0.05) among the filter media during five weeks of experiment.
There were significant differences (P < 0.05) among the treatments in unionized
ammonia (NH3-N) concentration at initial stage, third week and forth week of the
experiment.
