I'm picking up on an issue mentioned in a former post. Quite correctly it stated that danio and corys need to be in a group.
The reason is that these are "shoaling" fish. They live together in very large groups, sometimes hundreds of them, in the wild, and they see this as protection but also frequently there is a social order within that group. Fish that expect to be together will often become stressed on their own (or even with 1 or 2), and that makes them more susceptible to health problems. They can also become aggressive to other fish. So keeping shoaling fish in groups is important.
And that brings us to a 10g which is not enough space for a group of active swimming fish like danio. There are smaller fish that would be lovely in a 10g, several species under the cyprinids and one (Ember Tetra
) under the characins.
If the emerald cory is really a cory, namely Corydoras aeneus
, then a group of 3 in a 10g would be fine. But if it is the Brochis splendens
"emerald" then no, as this fish gets larger. Larger fish impact more on water quality as well as the physical space.
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