| A feedback based variable temperature-control system was developed for facilitating indoor aquaculture research. The system included sixteen independent tanks controlled by a personal computer using T-type thermocouples, a 32-channel multiplexer, two 8-channel analog to digital converter boards, and a set of 32 relays. Electric immersion heaters were used to increase water temperature, while a chiller and heat exchanger was used for cooling. Five centimeter PVC airlifts allowed for aeration and circulation of water. The system was initially used to simulate fixed and diurnal temperatures, but can be programmed to hold or varying temperatures from 5°C to 34°C in each tank independently. In one set of experiments, tanks were held at 10°C, 15°C and 20°C.... |
