What kind of pet fish will not eat a guppy?

It's tricky to give a definitive list of fish that *will not* eat a guppy, as individual fish personalities and tank dynamics play a big role. However, here are some general guidelines:

Good Tankmates for Guppies:

* Smaller, peaceful tetras: Neon tetras, cardinal tetras, rummy-nose tetras, glowlight tetras, etc.

* Peaceful barbs: Cherry barbs, tiger barbs (can be nippy, so monitor closely), gold barbs.

* Dwarf Corydoras: These bottom-dwelling catfish are great for cleaning up scraps.

* Snails: Nerite snails, mystery snails, etc.

* Shrimp: Cherry shrimp, ghost shrimp, etc.

Fish to Avoid with Guppies:

* Large or aggressive fish: Anything significantly bigger than a guppy, like cichlids, large catfish, or even some larger tetras like black skirt tetras.

* Predatory fish: These will see guppies as food, including larger barbs, angelfish, and any fish known to be aggressive or predatory in nature.

Important Considerations:

* Tank size: A larger tank allows for more space and hiding spots for the guppies, making them less vulnerable.

* Guppy numbers: Having a school of guppies can provide safety in numbers.

* Water parameters: Guppies prefer slightly alkaline water, so ensure any tankmates are compatible.

* Individual personalities: Some fish, even if usually peaceful, might be more aggressive than others.

* Observation and monitoring: Always monitor your tank carefully for any signs of aggression or bullying.

General Rule: If you're unsure, it's best to err on the side of caution and choose smaller, peaceful species as tankmates for your guppies.