What should I do if it rains in open-air fish farming?

If fish are raised in the open air, the dissolved oxygen will be reduced due to the decrease of air pressure in rainy days, which will make the fish float. At this time, oxygen should be given in time to prevent fish from dying due to lack of oxygen. In addition, after rainwater enters the fish tank, it may carry some pollutants, which will also lead to the change of water temperature. These all need attention. It is best to build a canopy in advance to avoid getting wet.