Do you have any specific questions?
Are you in the planning stages or do you already have goldfish?
Do you have any specific questions?
Properly housed and taken care of, common goldfish can get up to 10-12" and fancies about 8".
For fancies, 20g for the first fish and 10g for each fish is usually recommended. This may be a bit conservative. Common goldfish can be housed indoors while they are younger but ponds are more suitable for them.
Generally you don't clean the tank per se. Performing weekly water changes of 25%-50% should keep the impurities at a manageable level. Vacuuming the gravel can be performed during water changes. An adequate filter is essential as goldfish produce a lot of waste.
Another question is why is my fish always at the top of the tank ? And should my tank be all the way Filled with water ?
It might be in response to low oxygen and/or poor water circulation. What are you providing in terms of filtration and aeration?
For the most part, yes, filled up. More volume is usually better unless surface area is sacrificed.
I'm sorry to say but that tank is entirely too small for your goldfish. I don't see a filter, but even if you had one it wouldn't be suitable. You need to do a water change with treated, temperature matched water asap. Do you have access to a larger tank?
Try to test the water or have a fish store test it.
Goldfish need lots of very clean, cool, oxygenated water.
How much water did you change ?
GF can handle 90% water changes.
What did you use to dechlorinate your tap water ?
I would return the Goldfish, and research some small tropical fish or a Betta instead. They can stay in small tanks.
The problem is that Goldfish poop a lot so a small tank would get Ammonia quickly which can sicken or kill the fish.
Is this a 10gallon tank ?
Yes you changed most of the water, but do you have a filter (as someone asked earlier)?
Even if you change most of the water,(be prepared to do it every day) your tank is way too small for a goldfish.
Yes your fish is small now, but goldfish produce lots of waste and grow rapidly. This is why many goldfish kept in bowls or small tanks live very short lives. Their growth is stunted, imagine living in a closet. Goldfish (internet recommendations) need 20 gallon minimum for the first one and 10 gallons for each additional fish after that.
Many disagree with that recommendation (myself included), IMHO they should only be kept in very large tanks or ponds.
Again, do you have a filter?