Do You Need a Water Pump for a Fish Bowl?

Most aquarium hobbyists discourage fish bowls. They are seen as a relic from the days before people knew better, sold by pet shops to those who still don't. Very few fish can survive, let a lone thrive in such an arrangement, even with a water pump.

  1. Goldfish and Bowls

    • Goldfish do not grow to the size of their container.

      Goldfish bowls date back to antiquity. However, references going back more than a century report that experts knew these containers were a bad idea. Goldfish need an aquarium with a volume of 30 gallons per fish to thrive. While goldfish can survive in bowls, they won't grow to their full size or live their full lifespan. Goldfish can live for more than 40 years and grow larger than a foot if given enough space. To keep goldfish happy and healthy, keep them in an aquarium of sufficient volume with water pumps and filters. Unlike many aquarium fish, goldfish do not come from the tropics and do not need aquarium heaters in most homes.

    Bettas and Bowls

    • Male bettas only fight with other male bettas.

      Keeping bettas in bowls is more controversial than goldfish, in that some hobbyists argue they can live happy lives in well-cleaned bowls with weekly water changes. Bettas have an organ in their gills that allows them to breathe air when water conditions get bad enough. However, bettas do need warm temperatures to thrive, and most bowls are too small to accommodate an aquarium heater. Worse, some bowls are made of plastic and could melt if heated. While bettas thrive best in aquariums with real filters and heater, extra water pumps might not be a good idea, since they do not swim well in strong currents.

    Properly Stocking Aquariums

    • Saltwater tanks cannot support as many fish as freshwater aquariums.

      The biggest problem with keeping fish in bowls is the tiny volume of these containers. Tropical freshwater fish need at least a gallon of aquarium water per inch of fish. This guideline breaks down for fish larger than 3 inches, however. If you plan on keeping larger fish, you need to research the needs of each specific species. In an aquarium, you must have filters that provide mechanical, biological and chemical filtration. Water pumps that just move water around are optional in most cases, though some species benefit from the aeration provided by additional water moment.

    Nano Aquariums

    • Nano aquariums require expert attention.

      Some advanced aquarium hobbyists do attempt to keep fish in tiny aquariums or bowls. This type of aquarium is called a "nano" style aquarium and is considered challenging. While definitions vary, a freshwater aquarium of less than 10 gallons is generally considered a nano setup. Often these tiny setups only feature plants and shrimp. Others "cheat" by having larger volumes of water hidden in out-of-sight reservoirs.