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Koran Angelfish

Pomacanthus semicirculatus

Marine Marine Indo-Pacific

Famous for dramatic juvenile patterning of concentric white and electric blue rings that transforms into dusky mottled adult colours. It is a hearty, long-lived show fish that grows exceptionally large, quickly outgrowing standard aquaria. Sponge-rich foods are essential for optimal health, and corals are likely to be nipped.

Also called: Semicircle angelfish, Blue angel, Blue angelfish, Half-circled angelfish.

32 cm adult length, drawn to scale. deep body.

Outgrows a typical home tank. Check this fish against the adult size above before buying a juvenile. The minimum shown is the least it is kept in for good, not a comfortable size.
Saltwater species. The planner judges it with a marine rule set. A reef or fish-only tank takes months to mature and costs more to run than freshwater. See the marine page.

Try it in the planner Opens a tank sized to its minimum with 1 fish added.

What it needs

ItemValueBecause
Adult length 32 cm Used for the Space check: the tank must be long enough for the fish to turn round.
Smallest tank 650 L, at least 180 cm long estimated The least water and floor length this species is kept in for good, as a single fish or smallest group.
Extra water per added fish 150 L estimated What each further fish adds once the minimum is met.
Waste load Class 5 of 5 estimated How much waste an adult makes against its size. Feeds the Load check.
Temperature 23 to 27 C Stock sharing a tank need overlapping ranges.
pH 8.1 to 8.4 Compared with tankmates in the Water check.
Hardness GH 8 to 12, KH 8 to 12 Degrees of general and carbonate hardness.
Flow Medium Low-flow fish are stressed in a strong current.
Light Moderate Matched to the lighting class on the needs sheet.
Group size Single fish is fine Not a schooling species.
Temperament Semi-aggressive Territorial: strong.
Swims in Middle water Fish that use different levels share a tank more easily.
Lifespan About 15 years A fish is a long commitment.
Experience Some experience helps A guide to how forgiving the species is of mistakes.
Salinity Marine, about SG 1.023 to 1.025 Needs salt water, a different build and a longer-running tank than a freshwater set-up.

Tags marked estimated are judged from the size and habits of the species rather than measured, so treat them as a sensible default.

Diet and tank layout

Koran Angelfish is an omnivore that swims in the middle of the tank. It leaves most plants alone. Give it plenty of cover.

Tankmates

Works with

Depends

Avoid

Compare any two fish on the compatibility page, or print the equipment for a stock on the needs sheet. How this is worked out: the method.