By Species Maximum
Silver arowana: 90-120cm max, often 70-90cm in home tanks. Asian (red/gold): 60-90cm. Jardini: 50-70cm. Black arowana: 90cm+.
African arowana (Heterotis): 100cm+ but not a true arowana genetically.
Juvenile Growth Rate
Healthy 15cm juvenile grows 2-5cm per month for the first year. After 12 months, growth slows to 0.5-2cm per month.
By 3 years, most arowana reach 80-90% of max size. After that, growth is minimal.
Tank-Stunting Risk
Tank too small = stunted growth AND shortened lifespan. A 2m silver arowana in a 500L tank will only reach 60cm and die at 5-8 years instead of 15+.
Rule: tank length should be 3x predicted adult body length. 90cm arowana = 270cm tank minimum.
Diet Impact
Overfeeding = fatty liver + shortened life, not bigger size. Underfeeding = stunted growth + weak immune system.
2x daily feeds for juveniles, 1x daily for adults, with appetite that stops when offered second portion — this is the sweet spot.