fish tank vs marine museum

fish tank and marine museum both are nouns.

Word	Noun	Adjective	Verb	Adverb
fish tank	Yes	No	No	No
marine museum	Yes	No	No	No

As nouns, fish tank and marine museum are synonyms defined as:

fish tank and marine museum: a tank or pool or bowl filled with water for keeping live fish and underwater animals

Other synonyms of fish tank include aquarium.

fish tank (noun)	marine museum (noun)
a tank or pool or bowl filled with water for keeping live fish and underwater animals	a tank or pool or bowl filled with water for keeping live fish and underwater animals