Compare their water ranges
Freshwater angelfish: 24–30°C, pH 6–7.5. Guppy: 22–28°C, pH 7–8.2. A shared number is only a starting point; stable conditions and provenance still matter.
Plan for adult size and space
Use at least the larger baseline of 150 litres and 90 cm swimming length, then add margin for both animals’ full social groups, territory and waste.
Behaviour can override the numbers
Freshwater angelfish is described here as semi-aggressive; Guppy as peaceful. Introductions need observation and a ready separation plan. This assessment is not a guarantee of individual behaviour.