What is a tankbuster?

Tankbuster is the term given to freshwater tropical fish which grow huge and outgrow their tanks. It’s also been known for big, powerful fish to actually break tanks, usually by thrashing rocks against the tank glass with their tales. Big fish can break glass heaters too. 

Tankbusters usually grow to a length of two feet or more, making them way too big for average aquariums, and requiring custom-built tanks or tropical ponds. They are often cheap and widely available as juveniles, but they put on phenomenal growth and when they get big, few people can house them long term. Public aquaria are full of rehomed tankbusters and cant take in any more so large fish become worthless and are a problem for the hobby. Here are some of the most common tankbusters and their adult sizes:

  • Red Tail Catfish, Phractocephalus hemioliopterus, 60”/150cm
  • Arowana, Osteoglossum bicirrhosum, 36”/90cm
  • Pacu, Colossoma macropomum, 40”/100cm
  • Giant Gourami, Osphronemus goramy, 30”/75cm
  • Red Snakehead, Channa micropeltes, 36”/90cm
  • Tiger Shovelnose Catfish, Pseudoplatystoma fasciatum, 36”/90cm
  • Giraffe Catfish, Auchenoglanis occidentalis, 32”/80cm 
  • Ripsaw Catfish, Oxydoras niger, 40”/100cm
  • Pangasius Catfish, Pangasianodon hypophthalmus, 40”/100cm
  • Clarias Catfish, Clarias batrachus, 36”/90cm
  • Clown Knifefish, Chitala ornata, 36”/90cm 

It’s clear from the adult sizes of the species listed above that suitable forever homes would have to be huge, and be packing some serious filtration. Big fish are also long-lived (20 years or more,) so the cost of heating large aquaria and feeding such large fish would also have to be taken into account. If you want to watch such huge fish, a visit to a public aquarium comes highly recommended.

Even a 12″ fish can outgrow some home aquariums so always research species, their adult size and their long term care before making a purchase.  

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Jeremy Gay is an author, lifelong fishkeeper, and aquatic specialist. He's a former editor of Practical Fishkeeping Magazine, UK editor at Reefbuilders, a former aquatic store manager, and has collected fish in Sri Lanka and the Amazon. He's been on tv and radio, contributed to Koi Carp and Gardeners World magazines, been a product tester, a judge, and a product developer. Jeremy is here to guide and advise you on all things tropical, pond and marine, from set-up to stocking, health, feeding to breeding, as well as solving many common fishkeeping problems along the way.


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