guppies can live at 30 ℃, because they like to grow in warm environment, so they can still survive at 30 ℃. Although guppies can survive in the water temperature of 30 ℃, the water temperature of 30 ℃ is still relatively high for guppies. In high temperature environment, guppy will cause more discomfort. Common conditions such as slow growth, decreased resistance and easy illness will occur. In addition, in the high temperature environment, the oxygen consumption in the water will increase, and guppies are prone to lack of oxygen.

guppies can survive without oxygen, because their demand for oxygen is not very high. As long as breeders change their water regularly and keep the water clean, the oxygen in the water will be enough for guppies to absorb. Therefore, the breeder does not give them oxygen, and the guppy will not die.

However, when the density of guppies is too high, they will die if the breeder does not give them oxygen. At this time, the breeder needs to install an oxygen pump to keep sufficient oxygen in the water. However, it doesn't take too long to get oxygen. It takes 2-3 hours to get oxygen every day. In addition, in rainy weather or high temperature weather, breeders should also turn on the oxygen pump to ensure sufficient dissolved oxygen in the water.