Need hospital tank advise

OK the outbreak of Brooklynella or Ich whichever it was has killed all fish but my sixline, which shows no signs of stress no signs of parasites at this time, I have setup a hospital tank, should I just run it as a QT until it shows symptoms that can be diagnosed or start something like a ParaGuard treatment ?

I am leaning toward Brooklynella as it looked more like patches than spots, though there was no slothing or mucus and seemed to go from fish to fish once showing signs dead within a day.

Given how fast the fish die i would agree that you have brooklynella. I dont have enough experience with this parasite to give you any treatment recommendations, but i would recommend setting up the hospital tank and keeping ur dt empty for a while. You will have to allow the parasite to run through its lifecycle and starve to guarantee it will never come back. I haven’t been able to findany information on how long its life cycle is but if it’s similar to Ich then 4-6 weeks is a good starting point. A good way to test if its dead would be adding a highly susceptible species like clownfish. If it doesnt get brooklynella after 2-3 weeks then ur probably good.

Do u have any idea how u got it?

99.999% Sure it came in on the shells of a Clean Up Crew from reefcleaners as there have been no other additions for months.
Ya I got the six line out and in a hospital tank will leave DT fallow for 10 weeks.

i got a big old healthy damsel you can use to test the waters when you are ready. nothing seems to hurt this thing. its lived through every tank disaster ive had in that tank the past 12 years. and he bites real hard too. i wont mind if you test the water with it. Hee-Hee!!
PLEASE!!