I have 3 Angels in a 30 gal. - tall QT. The Rams I bought at the same time ended up with worms. I treated the tank but the Rams were too far gone by the time I figured out what it was and was able to get the correct medicine for it.
The Angels have not shown any signs of the worms, but I thought a longer than normal QT was required. 4 months later - 3 little Angels (smaller than a dime) now look like monsters in the tank. I would have never believed that they could grow that quickly.
I am trying to find a new home for my Silver Dollars so that the Angels can 'move on up'. It is only a 36 gal but it is long instead of tall - so it will give them a little more swimming room. I am waiting to see if they pair up - then I will move remaining Angel into another tank.