Care guide · Freshwater · fish
Altum angelfish care guide
Pterophyllum altum
The Altum angelfish (Pterophyllum altum) is a tall, demanding South American cichlid, not simply a larger form of the common angelfish. It needs warm, very soft and acidic water, a high aquarium and careful acclimation. Many fish in trade are wild-caught and may initially need live or frozen foods. Plan at least about 600 litres, 120 cm length and 60 cm water height for a group, and make sure you can maintain the specialist water conditions long term. Ask the seller which conditions the fish currently experience and confirm that they are feeding reliably before moving them into a new aquarium.
Plan your aquarium →At a glance
- Temperature
- 28–31 °C
- pH
- 4.8–6.2
- GH
- 1–5 °dGH
- Aquarium length
- At least 120 cm
- Minimum aquarium volume
- At least 600 L
- Adult size
- Up to 18 cm
- Group size
- At least 6 individuals
- Temperament
- Peaceful, Predator
About this species
Pterophyllum altum belongs to Cichlidae and is related to, but distinct from, the common angelfish P. scalare. It has a taller body and a deeper notch above the eyes. Seriously Fish gives about 18 cm standard length; the long fins make total height much greater. Check the identification with a specialist seller because young fish in the trade can be mislabelled.Natural habitat
The species occurs in Colombia and Venezuela, in the upper Rio Negro and tributaries of the upper Orinoco, including the Atabapo and Inírida. These waters are warm, soft and acidic, with slow flow. Submerged roots and marginal vegetation provide cover. Reproducing this environment requires stable water quality and careful acclimation; do not suddenly lower pH to imitate a wild habitat.Aquarium and layout
Height and swimming room matter for adults. A literature review cites 600 litres as a recommended spacious group aquarium and a minimum footprint of 120 × 60 × 60 cm; lower recommendations exist but are not equivalent for an adult group. Use at least about 600 litres, 120 cm length and 60 cm water height, preferably more. Provide fine sand, root wood, tall plants and floating plants to diffuse light, while leaving open swimming space. Avoid strong flow. Use a mature filter and keep nitrate low.Water conditions
Seriously Fish lists 28–32 °C, pH 4.8–6.2 and GH 0–5 dGH. A literature review reports partly overlapping natural conditions and 25–31 °C. We therefore show 28–31 °C, pH 4.8–6.2 and very soft water as the shared source range, not one universal optimum. Wild-caught, captive-bred and recently imported fish may be accustomed to different values. Ask the breeder or seller for current conditions and change temperature, pH and hardness gradually.Behaviour and group size
Altums are generally peaceful with larger, calm fish, but anything that fits in the mouth may be prey. Small tetras, guppies and pygmy rasboras are risky, and fin-nippers are unsuitable. Keep them in a group; pairs may later form and defend a spawning area. No named tankmates are linked as verified combinations on this guide.Feeding
Wild-caught Altums can be difficult to transition to dry food. Seriously Fish recommends regular live foods and a gradual change to frozen foods; captive-bred fish may accept flakes. Offer suitable small live or frozen foods and confirm that a fish is feeding before purchase. Vary the diet carefully and remove leftovers. Only try prepared foods gradually once it is feeding reliably; no exact product match has been confirmed.Breeding
Breeding is difficult and requires very soft, acidic water and stable conditions. Seriously Fish describes a pair forming from a group of juveniles. Remove the other fish once a pair bonds; six juveniles is not advice to keep six adults in a small aquarium. The pair lays eggs on roots or a similar surface and may eat early spawns. Prepare a separate spacious breeding setup before attempting it.Sources & review
This care guide draws on several specialist sources and was last checked on .