1. In the hot summer season, crucian carp will look for a water layer with suitable water temperature and dissolved oxygen. The water temperature will decrease with the increase of water depth, and the deeper the water temperature, the lower it will be. There is another magical place in winter. Even if the temperature is very low and the water depth exceeds 5 meters, the water temperature can reach zero, which is why ice fishing can catch fish. Dissolved oxygen will decrease with the increase of water depth. In summer, fish move a lot and need oxygen. Therefore, to sum up, crucian carp need to find the appropriate water temperature and dissolved oxygen depth, which is the premise of our floating fishing for crucian carp.

2. Besides the days with high temperature, there is also the weather with north wind blowing in summer. Wind will cool the upper water and increase dissolved oxygen. Under this condition, crucian carp will also float up, but the fish mouth is not bad, it will be very good. This is different from the floating head of fish in hot weather. Fish float in hot weather because the dissolved oxygen in shallow water is richer than that in deep water, and crucian carp can only choose the water layer rich in dissolved oxygen in order to survive at high temperature.