first off what size tank? are there fish in it already? is it cycled?
Anyways Im going to assume you have other fish in it. If not you dont need to worry about quarentine just put it in the tank.
Most people keep a sick tank/ quarentine tank in addition to their regular tanks for the reason you mentioned, Disease control. I had a 10 gallon for mine but it sprung a leak.
To quarentine you need a tank cycled preferably and empty of other fish and heated. Just put the fish in the tank for 1-2 weeks {2 weeks is my preference other people may keep theres in for longer or shorter times}and take care of it like you would your other fish. And keep an eye on it to make sure it is healthy and disease free. After that time passes if everything is ok with your new fish add it to your main tank.
The whole purpose is to make sure you dont introduce a healthy looking fish that you just got to a established tank and find out a day or two later it is/was sick and now all your other fish are now sick too.
Its a better safe then sorry measure, to preserve the health of your fish and prevent disease.
If you get several fish at the same time you can put them all in the quarentine tank togeather as long as the fish wont kill each other and the tank is large enough. hope this helped.
