APPLICATION OF THERMAL INSULATOR FOR HEAT STORAGE IN CATFISH PONDS

Water temperature was an important factor influencing the livelihood of aquatic animals including fishes. The low water temperature resulted in reduced feed intake and growth and lead to a shortage of fish production during the winter, as well as in the highlands region such the northern of Thailand, which the air temperature probably dropped below 15 degrees Celsius. For this reason, many researches had been done into finding methods for increasing the water temperature in aquaculture ponds, such using fish pond heaters, or using greenhouses to prevent heat loss from ponds. In this study, the using of pond insulation together with pond covering in order to store solar heat inside hybrid catfish (Clarias macrocephalus x C. gariepinus) ponds were conducted and evaluated the performance in increasing water temperatures. The results showed that using insulation together with pond covering not only increased the average water temperatures up to 6.3 degrees Celsius higher than the control, but also reduced the daily water temperature fluctuation. In addition, the catfish raised in the insulated ponds had better growth performances. The growth rates and survival rates were higher than the control up to 34 and 91 percent, respectively, while the feed conversion ratio was lower about 30 percent