A study was carried out to assess the culture performance of monosex and mixed-sex tilapia (Oreochromis niloticus) in underground brackish water by using semi-intensive integrated pond system. The experiment was conducted in three earthen ponds for a period of 11 months. In pond-1 (P1), 200 females and in pond-2 (P2), 200 males, while in pond-3 (P3), 100 male and 100 female tilapias were stocked. Salt-tolerant fresh biomass, i.e. Leptochloa fusca (Kallar grass), Brachiaria mutica (Para grass) and Kochia indica (Kochia) was used as supplemental feed. Fertilization of all ponds was done with goat droppings @ 6000 kg per ha and nitrophos @ 7.5 kg per ha. Results indicated that tilapia was found well adapted to the saline environment. The net fish production was calculated as 1295, 1752 and 914 kg per ha per year in female, male and mixed tilapia ponds, respectively. Male tilapia culture resulted in a significant (P less than 0.05) increase in fish production.

An indoor aquaponic system (i.e., the integration of fish culture with hydroponic plant production in a recirculating setup) was operated for maximizing water reuse and year-round intensive food production (Nile tilapia, Oreochromis niloticus, and leaf lettuce) at different fish feed to plants ratios. The system consisted of a fish culture component, solid removal component, and hydroponic component comprising six long channels with floating styrofoam rafts for holding plants. Fish culture effluents flowed by gravity from the fish culture component to the solid removal component and then to the hydroponic component. Effluents were collected in a sump from which a 1-horsepower in-line pump recirculated the water back to the fish culture tanks at a rate of about 250 L/min. The hydroponic component performed as biofilter and effectively managed the water quality. Fish production was staggered to harvest one of the four fish tanks at regular intervals when fish attained a minimum weight of 250 g. Out of the total eight harvests in 13 mo, net fish production per harvest averaged 33.5 kg/m³ of water with an overall water consumption of 320 L/kg of fish produced along with the production of leaf lettuce at 42 heads/m² of hydroponic surface area. Only 1.4% of the total system water was added daily to compensate the evaporation and transpiration losses. A ratio of 56 g fish feed/m² of hydroponic surface effectively controlled nutrient buildup in the effluents. However, plant density could be decreased from 42 to 25-30 plants/m² to produce a better quality lettuce.