If the tank in which the traffic light fish live is large enough and the breeding density is small, the dissolved oxygen in the water can satisfy the fish's breathing. In this case, even if oxygen is not added to the water, the fish can live normally. Moreover, the photosynthesis of aquatic plants and filters in the fish tank can also increase the oxygen content of the water, so the fish can survive without oxygen. However, when the size of the fish tank is small and the number of fish is large, the amount of oxygen in the water can not meet their normal breathing needs. At this time, if oxygen is not used, the fish will easily die of hypoxia. In this case, it is necessary to use the oxygen pump to pump oxygen into the water, otherwise the fish can not survive.
The minimum tolerance temperature of the traffic light fish is 20 ℃. Once the temperature is below 20 C, it may stop eating, do not like to swim, and even lower temperatures will lead to death. In order to ensure the healthy growth of fish, when the temperature is below 22 C, heating measures should be taken. A heating rod may be use to warm that aquarium. In winter, especially in the northern region, it is recommended to use heating rods to control the water temperature between 20 and 26 degrees Celsius. But if the water temperature can be maintained in this range, there is no need to use heating rods.
