Rats and fish can't put salt. This kind of fish is neither salt-resistant nor drug-resistant. They like the environment with sufficient oxygen and clear water, so they don't have high requirements on water quality, so they can be clean. Salt is mainly used to cure diseases, such as common white spot disease, head hole disease, etc., which can be treated by adding salt and heating up. Salt is mainly aimed at scaly fish, which mainly secrete mucus to protect the body surface and have certain resistance to salt to protect the water in the body. However, scaleless fish have no resistance in salt water, and they are more likely to dehydrate and die.

rodents and fish can be polybred together with some small and medium-sized fish. Because this kind of fish is docile in character, it is best to choose fish with good character, such as guppy, traffic light fish, lotus lantern, etc., to prevent rodents and fish from being bullied. They have low requirements for the surrounding environment, and are relatively easy to raise fish. They have high adaptability and acceptance to the water quality and the surrounding environment, and can be well mixed with other fish.

Ornamental fish, such as lantern fish, generally like to move in the middle and upper layers, while rat fish like to move in the lower layers. Their living spaces do not overlap, and they will not fight because of their active areas. Generally, docile fish can be mixed with rat fish. Moreover, rats and fish like to eat algae on the wall of the tank and food residues left at the bottom of the tank, so they will not argue over food.