There are many! For example, Ficus microcarpa, Pteris vittata, moss and other aquatic plants are suitable to be put into the tank. For small fish, you can add guppies, traffic lights and other fish tanks. If it is small, don't put too much, just put a few.

However, the best creatures to add are the small fish and weeds around, which are difficult to get by themselves, so you can buy them, because the fish bought in the store are not as adaptable as the fish native to the stream, although their appearance is worse.

You can tell me what kind of ecosystem your ecological trough is, so it is best to suggest that you add appropriate consumers, producers and decomposers to it.