The guppies are small ornamental fish, and the 40 cm aquarium is also a small aquarium. When raising guppies at ordinary times, it is no problem to use a 40 cm fish tank, but it can not be used as a fish tank for guppies to breed. Because the reproductive capacity of guppy is very strong, each reproduction can produce 80 to 120 small fry. Although the fry are small in size, they grow extremely fast. In less than a month, they can grow to about 1 centimeter. A 40-centimeter tank is completely inadequate for their living space. In a crowded environment, fish not only do not have enough space to swim, but also suffer from hypoxia and other conditions. Therefore, only guppies that are not in the breeding period can be raised in a 40 cm tank.
Although guppies are low aerobic fish, but its breeding density is not too high. Like adult guppies, their average body length is between 4 and 5 centimeters. A 40-centimeter tank can be used to breed guppies of this size, which can be controlled within 40. If the size of the fish is about 2 centimeters, it is no problem to breed 50 fish. But if you want to feed better, the breeding density should be reduced, but not less than 10, otherwise the ornamental effect is not good. Generally speaking, the optimal number of fish in 40 cm tank is 20.
