Angelfish and guppies are not an ideal default pairing. Adult angelfish can prey on small guppies and will readily eat fry, while guppies generally prefer harder mineral-rich water than angelfish are typically associated with. Long guppy fins can also become damaged in a tense community. If kept together, use a large aquarium and accept that fry survival will be low and adult compatibility may change over time.
A community should fit on behaviour, adult size and water chemistry at the same time. Angelfish and guppies only overlap partially on those three tests.
Predation is the biggest long-term risk
Adult angelfish are opportunistic cichlids. Guppy fry are obvious prey, and smaller adult guppies may also be vulnerable.
Hardness preferences differ
Guppies generally thrive with more dissolved minerals. Angelfish originate from softer-water environments, so extreme hard-water or soft-water setups can favour one species at the other's expense.
Long fins can attract trouble
Even without outright predation, repeated chasing or fin damage means the pairing is not working.
Do not use fry control as the reason for the pairing
Adding a predator to solve guppy reproduction is not a controlled stocking strategy. Manage livebearer sex ratios and population directly.
Related aquarium tools and guides
Frequently asked questions
Will angelfish eat guppy fry?
Very likely. Small fry are easy prey for adult angelfish.
Can adult guppies be eaten too?
Small adults can be at risk as the angelfish grows.
Is water hardness a problem?
It can be. Guppies generally prefer harder water than angelfish.
Sources and further reading
This guide separates general aquarium arithmetic from fish-welfare decisions. For species-specific limits, always check the needs of the fish you intend to keep.