Day 10, I'm stopping the treatment all together, I'm going to leave the water alone for another 3 days, then do a 75 gallons water change the following week, and 75 gallons every week after that. I'm not putting the powder blue back in the DT for another 8 weeks, and I know there's people out there that Herbtana didn't work but I also believe that you need to take action the minute you see a single fish "scraping" against the rocks to avoid a full blown infestation. I don't think Herbtana is strong enough to fight an all out "outbreak". Prestine water condition doesn't mean that the water in your "closed" system is better or equal to natural sea water, but that your must important water parameter readings are "ideal" for the survival of all the animals in your reef system. Also "ideal" and what would make "perfect sense" is to remove ALL the fishs from the affected reef tank and place them in QTing, but some times what's "practical" and what "makes perfect sense" doesn't apply in the real world.