you should change the water once a week, and vacuum the substrate every other week. to vacuum, you will need a python gravel vacuum and a 5 gallon bucket. you do not change all of the water, you only need to replace 50% of it. you can use tap water, but will need to add a dechlorinator to the new water before you put it in the tank or you can use RO water which you can buy at a pet store for $.25 a gallon , you can pour it straight in the tank. goldfish are pretty hardy so a slight temperture change should not effect them. enjoy your finned friend!
You know whats really good for a gold fish it also helps them live longer, if you use bottle water as the water, you should also change it like every 4 to 5 days. Goldfish are known to be really filthy because they poop a lot.
Goldfish make ALOT of ammonia and it's deadly if it builds up adding an aquatic plant will help keep the water clean and it will die due to to much ammonia before the fish so it could be used as a sign the water is gross
Every 2-4 days, goldfish poop a lot and food fouls the water, dont over feed, plus they need oxygen, they get it from the water. If you see the water going cloudy, then change it right away, don't wait until you see the fish gulping air from the surface.
it is good to change it every day like have 2 bowls then right before you go to sleep switch the fish into the other bowl and empty the other and fill it back up i do that and i had the fish for 4 years now
Maybe every few days. I used to have a goldfish. Goldfish tend to be dirtier than other fish. If you have a filter, then I think once a week is okay, but if you keep it in a bowl, you need to change it like every 4-5 days.