Scalyfur does not recommend choosing fish for a small, unfiltered bowl. The inherited list claimed that bettas, white cloud mountain minnows and Endler’s livebearers could thrive with minimal maintenance. It did not demonstrate that their adult space, social and water-quality needs would be met.
Plan the habitat before the fish
SPCA New Zealand opposes keeping fish in unaerated, unfiltered and unenriched aquariums such as traditional fish bowls. Start instead with an aquarium whose dimensions, equipment and furnishings suit the adult species. Hardiness or the ability to breathe air does not replace those requirements.
Use our reviewed betta, guppy and goldfish guides as starting points. They are not a combined stocking list, and their requirements are not interchangeable.
A filter needs to mature
OATA explains that a new filter does not yet contain an established population of the bacteria involved in processing fish waste. Prepare biological filtration before introducing fish, and use water tests to assess the aquarium rather than relying on clear-looking water.
Check ammonia and nitrite, maintain suitable temperature and make partial water changes appropriate to the setup and results. A fixed weekly water-change percentage is not a guarantee that a bowl is safe. Adding a snail also does not remove the need for filtration, suitable space or maintenance.
If fish are already in a bowl, seek a species-specific upgrade plan promptly. Do not make abrupt, unplanned changes in water conditions while moving them.
Sources checked
Replacement copy checked on 2026-11-08. This is a source-based editorial review, not independent veterinary review.