Zero, goldfish need very clean cool water and are very dirty fish.
A fish bowl is not a solution its what you keep your goldfish/ beta fish in :P
just a normal bowl from the local pet store or wal-mart i believe has them. they are just a medium bowl that costs about 5-15 dollars depending on what size you want. When i had gold fish i had 2 as well and i liked to give them space. it is your choice.
it depends how big the fish bowl is
small fish
If it is as old as a goldfish that can, it can.
The cheapest way to keep a goldfish is to keep it in a fish bowl.........as long as the bowl is big enough the fish will be happy there.
if your gold fish is small or medium fedd 3 to 4 small gold fish food
Bowls are not meant for fish. 1. all bowls are to small. 2. no filtration. Well..this is correct, but you can have a Chinese fighting fish without filtration but only one per bowl.
Yes, provided the bowl is large enough.
A fish needs 20 litres in a bowl
Yes, like all pet fish, goldfish need more oxygen than can be provided by just a bowl of water.
The first thing I would say is, "if you want what's 'best' for your goldfish, you will get rid of the bowl and get a reasonable sized tank/aquarium." The basic rule is 1" of fish needs 1 gallon of water. Goldfish (are really a pond fish) grow to around 12" in captivity so the minimum sized tank you need for one goldfish, (allowing for substrate (for plants to grow in) and about 1" space at the top) would be around 18 to 20 gallons. They like to nibble on all the 'Elodia sp' of plants. Myriophylum, Cabomba and Ambulia are also enjoyed but their favourites are definitely Elodia crispa and E.densa.