How big of a container would i necessitate for 5 Celestial Goldfish?

I really like these goldfish and was thinking of breeding them but my spair tank would be too small (it be my guppy nursery tank) as i would need to get a few as u cant tell mannish and female appart untill they mature, so i would need to buy a bigger one, but what size would be best and what size would be a minimum size?

Ive kept fish for years and bred guppy's for most of that time, so i know adjectives about setting the tank up and maintaining it, and ive be rearching the Celestial Goldfish so i know all about there wishes.

Thanks
I would at least bear 10 gallons of tank. But you can ask at a local fish specialized store, do not go to a regular pet store they do not know anything about these things, they are a short time ago there to sell stuff.
Wow.. 10 gal for 5 goldfish.. You obviously do not know what you are talking about. I would vote at least 60 gallons(absolute minimum), if not more. Goldfish get pretty voluminous and a large tank is needed for them to keep em for natural life. Also if you are going to be getting the absolute minimum tank size craft sure to over filter! Get like 2 or even 3 filters running on the cistern. Make sure that each one is rated for a larger reservoir. Goldfish pollute alot so water changes weekly are a must.
Answers:    Celestial goldfish will need 40 litres each, so for a group you are probably looking at something around 250 litres, however once they are fully grown you will need an even bigger cistern.
20 gallon givem room
Any planning or reccomendations for a 55 gallon reservoir??   I hold a 20 gallon cistern and i dont no wat freshwater fish to put surrounded by it i am polite at keeping not easy fish ?   Fin ROT! DISEASE HELP?   Good website (with honourable pictures) to research Plecostamus?