Goldfish can be mixed with tropical fish, but it's better not to keep them together for a long time. Specific reason is as follows:
1, food is different: The feed habit of goldfish is more miscellaneous, what can eat, so food respect is better choice. Most tropical fish feed on a vegetarian, carnivorous, or algal diet. If they are mixed together, they can not take care of the feeding habits of the two kinds of fish.
2, disposition is different: Goldfish disposition is milder, like gregarious. Tropical fish generally live alone and have a strong sense of territory. If goldfish are mixed with large tropical fish, they are easily bitten or even killed by them.
3. Different temperatures: Tropical fish generally require 25-30 degrees of water temperature. If the temperature is too low, tropical fish will stop their activities, reduce their food intake, and easily get sick. Goldfish like the temperature of 20-24 degrees, too high temperature will lead to lack of oxygen or death of goldfish. Therefore, it is not recommended to mix together.
together with more varieties of goldfish, you can choose different varieties of goldfish together, ornamental is also better. You can also choose to mix with freshwater fish such as koi and crucian carp, because their habits and environmental requirements are similar, and there will be no contradiction in mixing together.
