What kind of tank will I need for a fan tail goldfish?

Sure, that old glass fish tank will be just fine to use for a fan tail goldfish. Clean it well with a mixture of water and hydrogen peroxide. Hydrogen peroxide will sterilize the tank and clean it without leaving chemicals that will damage your new fish. Rinse well, make sure the tank doesn't leak before you set it up indoors. Then find a good place to set it up and decorate. Before letting your new goldfish out in the tank, leave it floating in a bag in the water for a few hours to get used to the temperature of the tank.

I love goldfish, they're beautiful fish. Keep in mind that in order to keep their beautiful golden color, you will need to put the fish tank in an area that gets a little sunshine every now and then. I know someone personally that put her goldfish where they hardly ever got any sun and they turned a whitish color over time. They don't need full sun, just somewhere that they can get some sun from a nearby window.

which could be ok for some fancy goldfish. because of the fact they are actually not speedy swimmers the smaller length of the tank wont worry them. as long as you have stable filtering fancy goldfish will prefer approximately 20 gal for a million, and 10 gal for each extra fish. because of the fact your tank is taller, this implies much less floor section, yet you may nonetheless be pleased with 4 or 5 super fish. Ian

You need one of those "fancy filtered tanks" for all goldfish actually. You need a 20 gallon tank for the fancy goldfish, with 40 gallon filtration. If you know her fish tank is 20 gallons+ then you can take it and wash it thoroughly, using no chemicals and just some warm water.

Common/comet goldfish need 55 gallons with 110 gallon filtration and are best suited in ponds.

I have two black moors in a jewel lido tank, with filter and light. Got it all for 60 out of a newspaper.

A SQUARE TANK. Like the ones in the army, i like those ones.

+2 points, need to be level 2.

You can use it but you have to think. Well i will have to buy a filter and stuff like that so think is it cheaper to buy a new one or keep that one.

Don't be lazy and google it. It's not that hard. I found the answer to that question the very first link i clicked on.