Keep the Cipro on hand. These nems are hard to keep health and from my experience pick up infections fairly easy. Ive had mine sense December and have had to treat it twice. Once when I got it and just a week ago. I added another nem to my sump to just hold for a day or two and it passed something to my healthy one. Both were cipro'ed and doing well now
Well I must be tremendously lucky then. I have never QTed any of my anemones in my current system. I have two Heteractis Magnifica in my system. One I've had for over 6 months and the other 3. I have a total of 24 anemones in my 180gallon
My experience has been that once you get a Mag acclimated to your system they are pretty hardy unless you have some significant water quality problems. I'd think in your case the second infection was a direct result of adding the second nem. My advice is once you get a healthy Mag don't try to add another one.