So ill just give you facts to speed this long
Cycling a 75 gallon tank used feeder fish
Tank was done cycling fish got ick and died
Treated the tank x2 for ick
2x 80% WC
ammonia 0
Nitrite 0
nitrite 0
Added 2 comet
Goldfish into the 75 gallon left them there for 8 hours
Came home the fish were just floating there (alive!) their tails look like they have fin rot from some of the images on google search they also look (please excuse me for incorrect term usage) ashey (sp?)
Like their skin was whiteish and looked like they needed lotion.
I moved them back to the old tank
The water is crystal clear and still 0,0,0 stats
Im not to familiar with fish illness since this is my first