One goldfish on it's own needs at least 20 gallons (75L). It's not just about their potential size, which is big, but the fact that they are very messy fish and produce a high amount of waste
Well it'll help if it has water in the tank?
Yes, goldfish are very messy. Goldfish need 10 gallons per fish, you actually need a 20 gallon tank or about a 70 liter tank for 2 goldfish. But the small tank will do while they are small, you will need to eventually get a larger tank.
If the goldfish is a fancy variety, it can live alone in a 20 gallon tank. Goldfish do not belong in tanks any smaller than this as they grow very large
Yes, the bigger the tank, the bigger they will grow. Yes. The more resources given to the goldfish * more oxygenated water, * aquarium plants, * room to swim, * cleaner environments, the larger the fish will grow
No you schould not have that many fish in a one gallon tank. Thats the size of a big betta bowl. And because they are goldfish it is worse their poops are toxins
Since an oranda is a type of goldfish, they will be fine together
Small or Big it should be kept in a huge tank with Filter and Oxygen 10 gallons per Goldfish At least
None. A single goldfish should have a minimum of 75L. You would be better off keeping small tropical freshwater fish.
It is classed as a very small tank and could only house about 5 inches of fish. (1 goldfish is a 10 inch fish)
Regardless of the type or size of goldfish the minimum acceptable size of an aquarium for a goldfish is 30 gallons. Buy a tank that is at least 30 gallons if you plan to have goldfish. You can comfortably fit 3 goldfish in a tank this size but no goldfish in a tank any smaller. Goldfish are essentially pond fish and need lots of space to swim; they will not thrive in a small aquarium.
None! 1 goldfish can grow anywhere from 5 to 12 inches! It wouldn't live long because goldfish stunt their growth in small (unhealthy) spaces.
Goldfish and such, about 4-6 Tropical Small like cardinals then about 8