Efficient feed management is essential in aquaculture, especially for bottom-feeding species such as shrimp that require feed delivery at the tank bottom. Most commercial automated feeders are designed for surface-feeding fish and are unsuitable for benthic organisms, leading to feed waste and uneven distribution. This study developed and evaluated an automatic bottom feeder capable of dispensing sinking pellets directly to the substrate. The system integrated a 3D-printed auger for precise feed metering and a closed-type centrifugal impeller positioned at the water surface to achieve radial dispersion of feed. An Arduino Uno microcontroller operated the impeller speed (285.98–586.85 rpm), feed mass (95.23–285.68 g), and dispersion time (2–8 s). A Box–Behnken response surface methodology was used to analyze the influence of these parameters on the mean radius spread of feed, supported by image-based uniformity assessment using OpenCV. Results identified impeller speed as the most significant factor (p = 0.010), with optimal dispersion observed at moderate speeds and longer spread durations. The system demonstrated reliable mechanical performance and precise control, providing a novel, programmable solution for uniform feed delivery in shrimp aquaculture and a promising foundation for scalable, automated bottom-feeding technologies.

Saba bananas are widely produced in the Philippines, mainly for food production. The peel of saba was characterized, and some physical properties of it were measured. The heating value, fixed carbon, volatile matter, ash, and moisture content of the peel were also determined. In predicting the elemental composition, the equation of Parikh et al. (2007) was used, yielding an air-to-fuel ratio of 6.92 kgair/ kgbiomass for combustion. A laboratory-scale prototype updraft gasifier was fabricated and tested for efficiency by boiling water on it. The size of the peel affects the ignition time of the syngas and the burning rate of the biomass. Flow rate affects the amount of heat produced and the equivalence ratio during gasification. Thermal efficiencies in different settings are less than 20% due to system heat loss. The highest efficiency was obtained with a low airflow setting, while the lowest efficiency was yielded at a high airflow setting. At an equivalence ratio of 0.208, about 500g of saba peel produced around 1562.63 kJ of heat with a thermal efficiency of 17.46%. For higher efficiency of the peel, it is recommended to design a gasifier that would decrease the system heat loss and process the biomass into briquettes or pellets for a more uniform mass and size distribution.