It is much better for the ifsh if you add a pump or filter in your tank.
HOPE THIS IS HELPFUL
No you don't need a tank to simply pump water from a lake. You would only need a tank if your using a pressure switch to turn the pump on and off.
Yes
no they need at least five gallons each. a thirty gallon tank is a good size tank to keep goldfish in.
You need a lot of things, unless you are raising goldfish in a bowl. You need: (for a tank) A filter A tank (not recommended under 5 gal.) Goldfish food Gravel Live or fake plants (underwater plants) Air pump (not required) Choice of decorations These can be very expensive sometimes, but it will keep your goldfish living longer and happier than in a bowl
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.
Goldfish do not necessarily need an air pump as they can breathe oxygen from the surface. Some fish that may benefit from an air pump in a 5-gallon tank are bettas, tetras, and dwarf gouramis, as these fish species prefer well-oxygenated water.
Actually, I think that temperature is about right for your goldfish. But if you seriously need to, you need to change the temperature of the air around the tank. I suggest keeping it in a cooler room?
While it isn't required that goldfish have an air pump in their tank. It can help your tank life by providing valuable oxygen to the fish. This isn't specific to just goldfish, as all aquatic life can benefit from the presence of a air pump. If you notice your fish swimming with their lips on top of the water level most likely they are trying to get air. This is especially true for tanks that have canister or over flow filters where the water is pumped and filtered without making contact with air.
My Fantail Goldfish did that alot the first time I got him. I think it might be that they need to relax or they might be scared.
Yes, like all pet fish, goldfish need more oxygen than can be provided by just a bowl of water.