Guppies and minnows have much in common. Guppies are small, colorful schooling fish. Minnows are a large family of freshwater fish, many of which are also small, colorful schooling fish. However, there are many different types of fish in the minnow family and you should know what to look for.
Guppies and most minnows have very similar requirements. You can keep either in a 20-gallon aquarium, though guppies will be fine in a tank as small as 10 gallons. Both fish should be kept in groups of at least six. Guppies and minnows school in the wild for protection, so keeping them in groups keeps them from feeling stressed. Your tank should also feature open areas for swimming and some cover to help them feel protected.
The one thing you really need to pay attention to is the temperature requirements of your minnows. Guppies are tropical fish, so you should keep their water between 74 and 82 degrees. Minnows are a big group of fish -- their family, Cyprinidae, includes almost a quarter of freshwater fish. As such, they have a wide variety of care requirements. Many come from subtropical and even temperate water, and need colder water. Almost any North American minnows require colder water than guppies. But there are many tropical minnows available, such as danios and barbs.
Minnows to Mix
There are numerous tropical minnows to choose from. In a pet shop, they will typically be called danios, barbs and minnows. You should research the specific species of minnow you plan on keeping with your guppies. However, zebra danios, cherry barbs and rosy barbs all make great companions for a guppy. They are all small, colorful schooling fish, with the exception of the cherry barb, which prefers to live in male-female pairs.
Minnows to Watch Out For
Not every minnow is a good companion for guppies. Some common species do require colder water, like the white cloud mountain minnow. A few are too aggressive to live with guppies, like the tiger barb. It's really, really important you do your homework and consider species for these types of incompatibilities. Almost any North American minnow should be excluded because of its temperature requirements.