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Fish that grow too big for small tanks

48 species need either a large minimum tank or grow large at adulthood, often both.

The species here either need a lot of water on day one, or grow into a lot of fish over a year or two. Both groups outrun starter tanks. The minimum litre count on each record is the floor for a stable adult life, not the smallest tank the fish can survive in. A 30 cm fish is still a 30 cm fish in 200 litres if the tank is only 80 cm long.

Read the adult-size figure on the species page before you read the price on the shop tag. Most "they grow to the size of their tank" claims are misread observations of stunted, organ-damaged fish that died young. If a species hits 30 cm and the tank you have is 80 cm long, the tank decides the answer and the answer is "not this fish".

Every row is a real profile in the live library; filters are field-driven, not hand-curated blurbs.

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