Health & Wellbeingsetting up my first ever freshwater fish tank, need to know how many fish should I put in my 55 gallon fish tank,
For small bodied fish (tetras, minnows, guppies, etc) the general "one inch of fish per gallon" rule will likely be fine. For larger bodied fish (goldfish, plecos, Oscars, etc), it should be closer to one inch of fish per 3 gallons of water.
Always use the full grown adult size when deciding how many fish to keep. Take into account schooling fish as well which should be kept on groups of at least 5-6 fish.
Updated on August 12th, 2025