Quarantine Tank Question

[yannifish]

I have been quarantining my fish in a 10 gallon tank up until now. However, I am considering adding a school of three chromis to the tank, and would need to quarantine them all at once. Would it be worth it to purchase a 20 gallon tank to be a quarantine tank? I have a 75w heater that I would prefer not to have to replace. Would a 75w heater be enough for a 20 gallon tank?
I'm also thinking of when I get my flame angel, it seems like a 20 gallon would be much better than a 10.
Thanks!

 

[florida joe]

20 better then 10 30 better than 20 and so on, you heater will be fine I assume you keep your house temp above 70

 

[yannifish]

Yeah, I think I'll get a twenty gallon. The extra water will be helpful.
I think I'll get a new heater too. The house can drop below 60 at night this time of year, so I'd rather be safe than sorry.
Does a flame angel have to be the last fish added to a tank? I'm going to a city that has a lfs this week, and would like to bring back a fish (or three if they're chromis). I would like an angel, but if it should be added last I'll wait.
I have a 55 gallon by the way.