a 30cm fish tank is relatively small. Generally, it cannot raise large or medium-sized fish, and the oxygen consumption of small fish is not very high, so it is no problem to use an oxygen pump. Especially when the fish tank has a filter system, it can bring part of the air into the water, so it can also supplement oxygen. Unless the breeding density is relatively large, too many fish are raised, and oxygen consumption is relatively high, oxygen pumps need to be prepared.
1. Floating head: When fish are hypoxic, the most common reaction is floating head. The so-called floating head is the fish swimming to the surface to breathe, looks like spitting bubbles. The situation of floating head is more serious, which shows that the oxygen in the water body is extremely scarce, and must be replenished immediately, otherwise the fish will die in large numbers.
2. Anorexia: Whether the oxygen is sufficient or not sometimes determines the vitality of the fish. If the oxygen is relatively low, the fish will be relatively lazy, and there will be anorexia. Even if it is fed, it will not eat. However, the situation of anorexia is divided into many kinds, not necessarily hypoxia, proper oxygenation did not recover, we should consider other ways.
3. Crouching in the tank: Some fish will crouch in the tank when they lack oxygen, that is, crouching at the bottom of the tank. This is usually a phenomenon that new fish will encounter when they enter the tank. After discovery, they should change the water properly and pay attention to supplementing oxygen.
