Here's why:
* Temperature preferences: White cloud mountain minnows prefer cooler water (60-72°F) than guppies (72-82°F). Maintaining a comfortable temperature for both species would be difficult.
* Breeding: Guppies are livebearers and reproduce prolifically, while white cloud minnows are egg-layers. Guppies may outcompete white clouds for food and resources, making it difficult for them to breed successfully.
* Water parameters: Guppies are more tolerant of a wider range of water parameters, while white clouds are more sensitive. Maintaining ideal water parameters for both species can be challenging.
However, there are some exceptions:
* Large tanks: With a large enough tank (at least 55 gallons), maintaining a temperature gradient and providing ample hiding places for the white clouds could be possible.
* Experienced aquarists: Experienced aquarists who are familiar with the needs of both species may be able to successfully keep them together.
* Species-specific breeding: If you are specifically looking to breed either species, it is best to keep them separately.
In general, it is safer and easier to keep these species separately. You can provide them with their ideal water parameters and ensure their well-being.
If you're unsure, it's always best to consult with an experienced aquarist or your local pet store for advice.