fish farm vs fish tank

fish farm

noun
  • A place or facility dedicated to the raising of fish or other seafood for sale. 

fish tank

noun
  • A container, usually made out of glass or acrylic, specifically designed for holding water and marine life. 

  • A section of a prison for newly arrived inmates. 

How often have the words fish farm and fish tank occurred in a corpus of books? (source: Google Ngram Viewer )