Originally Posted by mtsuguy
I only have a 10g QT, do I only need to do one fish at a time? I know bigger is better when it comes to saltwater but frankly I just dont have the money to spend on a 30g setup that I'm only going to use 4 weeks and be stuck with.
It really depends on the overall size of your main tank, and you shouldn't be getting that many fish at one time anyway. A tank that's 25-50% of the size of your main display tank is fine for QT, but if you'll be housing bigger fish, it's better to have a bigger tank. And for adding fish, you should really only add one or two fish per month, no matter the size of your tank. The reasoning there is to keep your tank stable between additions. The more fish you add, the quicker the bioload change, which can disrupt the biological filtration (bacteria growth, pods, etc) and add a lot of extra waste/food all in one shot. 4 weeks definitely won't be long enough to QT all new incoming fish to stock a tank.
And you won't always just need it for the initial stocking. If a fish gets sick you should pull it out and place it in QT asap just in case it's something that can spread to other fish, to treat it, and also to reduce it's stress while you treat it.