Keeping Oscars With Guppies: A Bad Idea!

Thinking of keeping a mighty oscars and guppies? It’s not a good idea. Keep reading to find out why.

Oscars With Guppies: Size Matters

Oscars are simply too big to be kept with guppies.

oscars and guppies make bad tank mates
This oscar is big enough to swallow guppies whole!

It’s not just that oscars grow as large as 14 inches (around 56cm) while guppies stay as small as an inch (3cm), it’s also that oscars are quite ruthless predators. In the wild, oscars mostly prey on invertebrates. However, they are very opportunistic feeders and will not turn down the opportunity to devour little fish too! And that’s what your guppies will be to an oscar: delicious, little snacks.

Oscars With Guppies: Water Parameters

While the size difference makes water parameter compatibility somewhat of a moot point, it is nevertheless worth comparing the two.

Oscars come from the soft, acidic waters of the Amazon basin. Whereas, guppies prefer harder water. However, guppies are an extremely adaptable species and can cope in non-ideal water chemistry.

However, both guppies and oscars are very much domesticated ornamental fish. This is relevant because over many captive bred generations they become more tolerant of typical tap water conditions. As such, water chemistry would not be a stumbling block to keeping guppies with oscar cichlids.

An oscar’s ideal temperature range is 72°F – 80°F (22°C – 27°C) which is the same temperature range guppies enjoy!

Conclusion: Don’t Keep Oscars And Guppies Together!

It might be tempting for a newcomer to the hobby to throw a baby oscar into their community tank containing guppies. After all, a tiny baby oscar is far too small to eat guppies. But, beware, oscars are very fast growers and within a matter of weeks your new oscar will have grown big enough to start dining on your guppies.

Instead, consider alternative tank mates. For example, house other small community fish with guppies: zebra danios, tetras, corydoras catfish. While your oscar will cohabit better with large schooling fish like tinfoil barbs, bala sharks, and silver dollars.

Further Reading