I just tried treating two colonies that were purchased at the same time and judging by the rocks and zooanthids, were collected from the same place. I treated one with doxy, one with Furan2 and the Furan2 rock looks much better, not sure of long term success but if you are to treat, the Furan2 is a better choice then the doxy. I'm awaiting results on the swabs taken from the colonies to see whats actually cooking here.
Will probably do a follow up treatment with the Furan2 this week.