Koi Angelfish
Pterophyllum scalare
The Koi Angelfish (Pterophyllum scalare) is a semi-aggressive fish that's a good step up once you have a little experience. Give it a tank of at least 180 litres (48 US gallons), water held at 75-86°F, and a pH of 6-7.5.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
South America
- South America
Regional colours match the stocking calculator's origin map.
Koi Angelfish Tank Setup
Give them at least 180 litres (48 US gallons). Cichlids are territorial and produce plenty of waste, so strong filtration and some rocks or wood to break up sight lines both help. Aim for 75-86°F and a pH around 6-7.5. They reach about 15 cm as adults, so don't be misled by the small juveniles sold in stores.
What Do Koi Angelfish Eat?
They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.
Koi Angelfish Tank Mates
Koi-patterned Angelfish morph. Predatory toward small fish and inverts. May nip fins of long-finned tankmates. The Koi Angelfish is semi-aggressive, which is the first thing to weigh up when you choose tank mates. It's a known fin-nipper, so avoid bettas, guppies, and other slow, long-finned fish. It's predatory, so anything small enough to fit in its mouth will be treated as food rather than a companion. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Koi Angelfish Good for Beginners?
Not a sensible first purchase. Get the tank cycled, keep easier fish stable for a year, then revisit if you still want the extra work this species demands.
Koi Angelfish - frequently asked questions
What size tank do Koi Angelfish need?
Koi Angelfish need a tank of at least 180 litres (48 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
What water parameters do Koi Angelfish need?
Keep them at 75-86°F with a pH of 6-7.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Koi Angelfish eat?
Koi Angelfish are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Koi Angelfish good for beginners?
Koi Angelfish are best for keepers with a little experience. They are manageable once you test water regularly and catch problems early; a complete beginner may prefer something more forgiving first.
Common mistakes with Koi Angelfish
- Underestimating tank size - the minimum footprint is 180 litres (48 US gallons); impulse buying into a smaller tank leads to stress and shortened lifespan.
- Mixing with long-finned fish - Koi Angelfishs will nip at bettas, angelfish, and other fish with flowing fins, causing stress and infection risk.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Fish to avoid mixing with Koi Angelfish
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates
- Cardinal TetraSize risk - Koi Angelfish will likely eat Cardinal Tetra at adult size
