Quick Stats
| Adult Size | 15 cm body; 20 cm+ tall with fins |
| Minimum Tank | 30 gal (tall), 55 gal for a group |
| Temperature | 24–30°C |
| pH Range | 6.0–7.5 |
| Hardness (GH) | 3–8 dGH |
| Difficulty | Medium |
| Temperament | Semi-aggressive, territorial when breeding |
| Diet | Carnivore — pellets, frozen bloodworm, brine shrimp |
| Schooling | Pairs, or groups of 5–6 to spread aggression |
Tank Setup
The freshwater Angelfish (Pterophyllum scalare) is a South American cichlid from the slow rivers and flooded forests of the Amazon basin — an ambush predator shaped by its habitat: laterally compressed to slip between submerged branches, tall-finned to present a large silhouette in dim water. Translating that into an aquarium means one thing above all: height. An adult angelfish runs 15 cm long and over 20 cm tall with fins, so the standard 30-gallon breeder (45 cm tall) is the realistic minimum for a pair, and 48 cm-plus of height is what lets the fish actually develop its full finnage.
Target 24–30°C, pH 6.0–7.5, and hardness 3–8 dGH — soft, warm, slightly acidic water. The decor script writes itself from the habitat: tall vertical structure — driftwood, swordplants (Amazon swords are the classic), and Java fern on wood — with open midwater for cruising. Moderate flow, dim-to-moderate light, sand or fine gravel substrate. Angelfish are gliders, not sprinters; strong current stresses them permanently.
Buy juveniles and grow them out if you want a bonded pair (more below), and give a group of five or six a 55-gallon-plus tank. Solo angelfish exist but are lonelier, duller versions of the species. Plan the whole community around the angelfish's adult size — the single most common mistake with this species is a 15-gallon community tank bought around juvenile angelfish the size of a coin.
Tank Mates
Angelfish are peaceful cichlids by cichlid standards, and that sentence contains both halves of the truth: they ignore most tank mates completely, and they are still cichlids — ambush predators with jaws that can handle anything that fits. The compatibility question is therefore mostly a size question, plus a breeding-territory question.
Reliable companions: fish that are too deep-bodied or too large to eat and too calm to nip. Rummy Nose Tetras and Cardinal Tetras work at adult size in warm water (grown together or bought large — see the cardinal profile for that conditional), as do Pearl Gouramis, larger livebearers, Bronze Corys and Sterbai for the floor, and Bristlenose Plecos on the wood. Silver dollar tetras and other 5 cm-plus midwater fish are the safe rule of thumb.
The avoid list is where honesty matters: neon tetras (Paracheirodon innesi) are angelfish food in every tank where the angels grew up first (wild angelfish stomachs literally contain tetras — this is not speculation), guppy (Poecilia reticulata) fry and shrimp are hunted by adults, and fin-nippers (tiger barbs, serpae tetras) destroy the veil fins that make the species worth keeping. A breeding pair changes everything: spawning angelfish claim a 30 cm radius around the spawn site and patrol it aggressively — in a 30-gallon tank that is half the swimming space, which is why the community tank guide recommends planning angelfish tanks at 55 gallons when you intend to let pairs form. Bolivian rams and angelfish usually coexist — different water columns, different aggression triggers.
Diet & Feeding
Angelfish are carnivores — in the wild, insect larvae, small fish, and crustaceans picked from cover. In aquaria they accept pellets and flake readily, but their condition, growth rate, and breeding readiness come from frozen and live protein: bloodworms, brine shrimp, daphnia, and (for conditioning pairs) live blackworms. A protein-forward diet is not optional for this species.
They are deliberate midwater feeders that strike at slow-moving food. Floating-only or fast-sinking-only feeding programs miss them; feed a mix that spends time in the water column. Two feedings daily, with a fasting day weekly, keeps adults in shape — angelfish are surprisingly prone to overfeeding-related fatty degeneration in mature tanks.
Beware two feeding-specific behaviours: adults will eat anything that fits in their mouth (this includes tank mate fry and shrimp), and juveniles fed on flake-only grow slowly and never develop the tall finnage the species is bought for. Growth rate tracks protein quality closely for the first year.
Common Health Issues
Angelfish are moderately hardy cichlids with a few known weak points. The most common presentation in new fish is ich following transport stress; treat early with heat (see the ich guide). The most serious reputation the species carries is for hexamitiasis (hole-in-the-head disease, caused by flagellate parasites) — head-and-lateral-line erosion connected to long-term poor water quality and vitamin-poor diet. It is largely preventable: high-quality water changes, a varied frozen-food diet, and vitamins; established cases respond to metronidazole-laced food.
Fin damage from nippy tank mates is the other common condition, and it is environmental: the shredded veil fin you are treating belongs to the tank mate choice, not the medicine cabinet. Damaged fins regrow if the nipping stops and water is clean; secondary fin rot (see the fin rot guide) needs prompt treatment.
The long-term killer is the boring one: chronic nitrate. Angelfish are big-fish-in-mid-size-tanks — high bioload, modest volume — and the nitrate guide is the most relevant health document for this species. A weekly 30–40% water-change rhythm keeps adult angelfish in breeding condition for years; neglected water is visible in their finnage within weeks.
Breeding
Angelfish form pair bonds and are substrate spawners — they lay eggs on a vertical surface: a cleaned leaf, a slate, the filter intake, or the aquarium glass. Pairs form from groups of five or six juveniles grown together; buy six juveniles, let them sort themselves out, and rehome the extras once a pair claims a corner. Unlike most cichlids, angelfish are serially monogamous: the pair typically stays together across many spawns.
A spawning run goes: the pair cleans a site → the female lays rows of eggs → the male follows fertilising → both parents guard and fan the eggs for the 2–3 days to hatching. At this point you choose: leave the family together (the parents move fry to a pit and guard them, an extraordinary thing to watch, but community tank mates — and sometimes the parents themselves — will eventually eat them) or pull the slate to a hatching tank. First-time parents commonly eat the first few spawns; patience or artificial hatching in a 1-gallon tank with methylene-blue water solves it.
Fry are tiny: free-swimming about a week after hatching, needing baby brine shrimp from day one (no infusoria stage — they grow fast). Angelfish fry grow quickly on live BBS and frequent water changes, and the pairing-plus-guarding behaviour makes angelfish one of the most rewarding cichlid breeding projects short of discus. For the full escalation ladder, see our discus guide — the angelfish's larger, fussier cousin.
Frequently Asked Questions
How tall does an angelfish tank need to be?
At least 45 cm (18 inches) for a pair, and 48 cm-plus is better. Angelfish are 15 cm long but over 20 cm tall with their dorsal and anal fins, and the finnage develops fully only with vertical room. Standard 30-gallon breeders (91 × 46 × 45 cm) work as the minimum for a pair; "tall" 30-gallon formats (61 cm high) work even better in small footprints. Height is the single most-cited regret in angelfish tank selection.
Will angelfish eat neon tetras?
Usually, yes, if the angelfish grew up first. An adult angelfish mouth handles a neon tetra without difficulty, and the predation is opportunistic rather than active hunting — but in an angelfish tank, neons disappear steadily. Adult cardinal tetras (Paracheirodon axelrodi) and other deep-bodied 4 cm-plus fish are far safer. If you want angelfish with small schooling tetras, add the tetras first, at adult size, and accept the risk anyway.
How do I get a breeding pair of angelfish?
Buy five or six unrelated juveniles and grow them together in a 55-gallon-plus tank. Pairs form naturally as they mature — you will see two fish claiming a territory and cleaning a vertical surface together. Rehome the unpaired adults once the bond is clear. Buying a "proven pair" costs far more and adapts worse; growing your own gives you a pair already at home in your water and your tank.
Are angelfish good for beginners?
For a patient beginner with the right tank, yes: they are hardy, forgiving of routine mistakes, and eat anything. The caveats are honest ones: they need a genuinely tall tank, they limit your tank mate choices (nothing small enough to eat, nothing that nips), and a breeding pair becomes aggressive to the whole community. Start with juvenile angelfish in a 30-gallon-tall planted tank with corys and large tetras, and the species is one of the best first cichlids.