You should be able to mix and match most of the fish listed in this article and not encounter any behaviors issues. That said, be aware that it simply isn’t possible to know for sure how a fish is going to interact with tankmates. We can predict based on the typical behavior of different species, but until you put your tank together you won’t know for sure.

Temperature

While many people may claim that keeping a freshwater aquarium is simple, when working with a basic aquarium set up there are certain aspects that you should keep in mind in order to help your aquarium to thrive. It is important to remember that the temperature of any aquarium needs to be maintained within a steady range in order to support the life within the tank. Most people are able to maintain the required temperature for the fish selection in their aquarium; however, many people neglect the plant life that they place within their aquarium which is equally as dependent upon the temperature of the water. It is crucial to select fish that thrive within a similar temperature range as well as plants that can be maintained in this same range in order to promote the optimal aquarium atmosphere. The average temperature for a freshwater fish community is between 72 to 82 degrees Fahrenheit. For plant life the average temperature falls between 76 to 86 degrees Fahrenheit.

pH

The pH (aka potential of hydrogen) of the water in the tank is also another important factor for any aquarium. Different types of fish require different pH balances in the water, while some thrive in a much more acidic atmosphere others may not. It is important not to mix fish that require a more acidic aquarium with those that require a less acidic aquarium in order to promote the health of your fish. Mixing two varieties of fish that have different pH requirements will eventually lead to the death of one of the fish types within the aquarium. As with temperature, pH is another factor that not only influences the health of fish within the tank, but it also affects the health of plant life within the tank as well. The average pH of a freshwater fish community is between 6.5 and 7.5; the average pH requirement for fresh water plant life is 6.0 to 7.5.