Fish and invertebrates are cold blooded and hence you must be aware that their body temperature is controlled by the temperature of the habitat they live in. Water temperature in fish tank or Aquarium hence is a very important factor. Sudden fall or rise of even 5 degree temperature will become fatal for the fish. Hence its recommended to keep the water temperature stable. The fish requires optimal temperature range and not extreme. In India, certain regions are prone to extreme climate. The variance between day time temperature and night temperature varies from 5 degrees to 25 degrees. These can cause same change in water in a pond or fish tank. In such conditions we recommend use of heaters and chillers / aquarium fans. Continues cycles of temperature variance in water can cause stress to the fish and stress can cause various disease because during high stress the immune system doesn’t work properly. More over increase in water temperature also decreases the Oxyge...