Pterophyllum altum, commonly called the True Altum Angelfish, is the largest and most majestic species in the angelfish genus. Native to the Orinoco River Basin in South America, Altums are highly prized for their towering body shape and elegant vertical striping.

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🌿 Key Identification Features

Here’s how you know it’s a true Altum:

• ✔️ Extremely tall, laterally compressed body

• ✔️ Distinct “notch” or dip above the eyes (very important ID marker)

• ✔️ Long, flowing dorsal and anal fins

• ✔️ Silver body with bold vertical black bands

• ✔️ More delicate and refined appearance than common angelfish

Many fish sold as “Altum” are actually scalare variants — true P. altum are noticeably taller and more dramatic.

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📏 Size & Growth

• Body Length: 15–18 cm

• Total Height (including fins): Up to 35–40 cm

• Lifespan: 8–12+ years

They grow tall rather than long, so tank height matters more than tank length.

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💧 Ideal Water Conditions (Very Important)

Altums are more sensitive than standard angelfish.

• Temperature: 27–30°C

• pH: 4.5–6.5 (acidic preferred)

• Hardness: Very soft water (0–5 dGH ideal)

• Stability: Extremely important — avoid sudden changes

They thrive in blackwater-style setups with tannins and subdued lighting.

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🏡 Tank Requirements

• Minimum Tank (Juveniles): 120L

• Adults: 300L+ tall aquarium

• Tank Height: 55–60cm minimum recommended

• Driftwood branches & Amazon biotope décor

• Dim lighting to reduce stress

These are not beginner fish — they demand stable, clean conditions.

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🐟 Temperament & Compatibility

• Semi-peaceful but hierarchical

• Best kept in groups when young

• Can pair off as adults

• Compatible with Discus, peaceful tetras, larger Corydoras

• Avoid aggressive cichlids and fin nippers

During breeding, pairs can become territorial.

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🍽 Feeding

• High-quality cichlid pellets

• Frozen bloodworms, brine shrimp, mysis

• Occasional live food for conditioning

Feed small portions 2–3 times daily for optimal growth.

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🌟 Why Altum Is Special

• Tallest angelfish species in the world

• Wild-type elegance unmatched by hybrids

• Highly sought-after by advanced aquarists

• Stunning centerpiece fish in tall aquariums

If you’re building a serious South American display tank, Pterophyllum altum is basically royalty.