The ideal water temperature for aquatic organisms are cultured should happen is not striking the temperature difference between day and night (no more than 5 ° C). On the stagnant waters which have a minimum water depth of 1.5 meters will usually happen coating (stratification) temperature. This happens because the coating surface temperatures higher than the temperature of the water at the bottom.
In the stagnant waters, based on differences in heat at any depth, water can be grouped (stratified) into three, namely:
a) epilimnion layer, the upper layer of warm water with a relatively small drop in temperature, the entire future water well mixed because of the wind and waves
b) the thermocline layer or metalimnion, which is the middle layer which has a very sharp drop in temperature, in this area every additional depth of 1 m, the temperature will also be reduced by 1 ° C
c) hipolimnion layer, which is the bottom layer which is padalapisan temperature differences are very small and relatively constant. on this layer hardly occurs mixing of water masses so that the temperature is relatively cold.
The temperature stratification occurs due to the influx of heat from sunlight kedalamkolom water resulted in a temperature gradient vertically. At the pond water depth of less than 2 meters usually occurs unstable temperature stratification. Therefore, for the fish farmers who undertake activities budidayaikan water depth should not lebihdari2 meters. In addition to break down the temperature stratification in the container of fish farming needed a tool by using an aerator / blower / waterwheel.
These properties are unique properties of water and are very important in the spread (dynamics) of heat in the water. With properties unique water, then the water supports:
a) The life of the organism in winter, because the water just freezes on the surface.
b) With temperature changes slowly, aquatic animals able to adapt to any changes in the properties of water.
Heat source that greatly affect the temperature of the water mainly from:
a) The radiation (radiation) directly from sunlight.
b) Condensation (Pengembusan) of water vapor.
c) The heat from the bottom waters (the center of the earth).
d) The effect of heat from the atmosphere.
e) The heat from the chemical processes in water.
Being the factors that affect the decline in water temperature is in general from:
a) Evaporation (evaporation).
b) reflection / heat release back.
c) reflection of sunlight back into the atmosphere from the water surface.