Yes it/they can. Care should be taken to let the temperature of the water the fish is/are in slowly equalise with the water in the pond before releasing the fish otherwise it/they may die from temperature shock. I used to place a bucket containing the fish in its/their original water beside the pond and slowly replace a cupfull of water at a time over about 30 mins or so before releasing the fish into its new home.
snails
It is important to remember to put things in a goldfish tank, even goldfish get bored. Some of my suggestions for tank decor are artificial plants and a "hidey hole" for your goldfish.
goldfish, koi
no werdos of corse not
about half an hour to an hour
No. Unless you put it in a tank with sand.
Yes you do!!
You have several choices, get a larger tank for them or put them into a pond (where goldfish should be) or remove some and take them back to a pet shop. Whatever you decide to do is up to you. You may even be able to think of some other alternatives.
Koi is a type of fish. Just don't put koi in the pond and it will not be a koi pond.
just put marbles and sea shells
best to do flake or pellets food feed 3 times a day do how many about 2 or 3 per goldfish not too much. Do tropical or goldfish food to feed goldfish. They need cold water or as warm as tropical fish in degrees. You can put tropical with goldfish.You can put goldfish outside in a pond. WARNING! DON'T PUT TROPICAL IN POND OUTSIDE OR THEY WILL DIE! I MEAN IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Most fish including goldfish naturally (instinctively) hide when a shadow passes over their water. If they come to the surface when they see a shadow passing over the tank/pond, they are assuming that food is going to be put there. This is a learned and remembered response. (Who said Goldfish only have a 3 second memory?)