Goldfish is the most suitable fish for raising in small pools, which is small in size, numerous in species and different in color. As a wide-temperature fish, there is no need to worry that low temperature will have too much impact on it. Among goldfish, the best one is grass gold, and other varieties can also be raised, but it is difficult to raise egg species, and it is not suitable for viewing in the pool.

The scientific name of Tangyu is Baiyun golden silk fish. This is an endemic fish species in China, mainly distributed in the southern region, and belongs to the national second-class protected animal. Because it has become extinct in the wild, it can only be raised artificially at present. It is worth mentioning that it has good cold resistance and can endure the ambient temperature of 5 ℃, so it is no problem to keep it in a pool.

Koi is bigger, but it is also more beautiful in shape. It should be noted that if Koi is raised, it is not suitable for raising other small fish, otherwise it will eat them. As a relative of carp, its adaptability to temperature is also very strong, and it can eat a lot of things, so it is easier to raise.

Medaka is mainly Guanbei Medaka, which is also a rising variety in recent years. Compared with many common small ornamental fish, the medaka has two characteristics, one is that it can endure lower water temperature without heating. The other is that as a back-watching fish species, it is not suitable to be raised in a big fish tank, but it is better to watch in a fish pond.

sole catfish is usually used as food fish, but it also has certain ornamental value, and has strong adaptability to temperature and likes still waters. Its food habits are miscellaneous, and it usually feeds on algae. It should be noted that its reproduction depends on mussels, and it is difficult to reproduce successfully without mussels.