depends on the fish and the bowl size/ opening
most ppl think goldfish in a bowl and either left until the water is so cloudy you cannot see the fish and then full empty and fill up straight from the tap
using the correct size bowl and fish and keeping on top of cleaning then you can have good results
most ppl think goldfish in a bowl and either left until the water is so cloudy you cannot see the fish and then full empty and fill up straight from the tap
using the correct size bowl and fish and keeping on top of cleaning then you can have good results