My 8w QT
beautiful purple tang, cured of ich with hypo, kept at proper salinity for a week extra before transfer, finally rejoined my main (that has never had a documented case of ich) about 2 weeks ago. Two lovely weeks go by and I'm thinking we're finally free of that dastardly parasite.
Then one day there it is....? Or isn't it??? On his left side there were 2 or 3 spots that I would swear were ich. On the other side maybe one... maybe 2. I upped his feeding, increased my use of garlic and selcon, hung more nori than usual, and prayed a LOT. Day two and those spots were gone. Ich can give you that rotten false hope so I didn't breath for two or three days. It's been 4 or 5 now and he's clear as a bell still. I don't know if they really were ich or just sand, settiment, ?whatever? but after that one brief appearance they've disappeared again. I guess we'll just play the wait and see game with them.
I'm starting to join the "it's in every system" camp. Unless you hypo every fish and QT
for 8w in a fishless system every single other addition to the tank how does anyone ever really know if they've got ich or not? Not until that one stress event that causes the outbreak will it be apparent.