Here is the treatment protocol for sick nems and cipro.
This is a re-post of what I wrote in ReefCentral on 3/09/2013 Many anemone keepers know, the collection and shipping process from ocean to local fish store (LFS) is a stressful event. Most host anemones do not survive this process without help, especially H. magnifica and S. gigantea. Other...
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I would suggest following it exactly as written.
For removing the nem, a nem cannon more than likely will not work. My suggesting is to use a very cold spoon to touch the foot fo the nem an entice it to let go of the rock. The removal does cause some stress, but the nem needs to come out of the tank. In the shape the nem looks to be in, you may be able to gently "peel" the nem from the rock. Trick here is to be patient and take your time. If you can get a little bit of the foot to detach, just touching the remainder will usually get them to release.
From there, just follow the treatment above.
For the WC part, it is not an issue to change 100% of water with a healthy nem. Some BTA may split if the alk or SG is way off, but for a sick nem IT IS ANOTHER STRESSOR, that needs to be avoided if you are going to remove and treat.. The fact you are removing it and then putting it into a QT tank is enough stress as it is.
For the treatment above, I would suggest using old tank water for the first day of treatment and then 100% new SW for the remainder. With it being a BTA, you can scale everything down to a 2.5 gallon tank if you want. This saves on water and the amount of cipro you use overall. Just be sure to watch for cloudy water. If that happens, 100% water change and redose back to therapeutic levels.