Ick lifecycle/reinfection question.

[maury]

Have a question for you folks in the know. I have recently moved my purple tang from my 55 to my 210. Now this fish, when I first got him when he was little, broke out with serious ick when moved to my 55. By feeding garlic, he beat it and did well. During his term in the 55 tank, there were a few episodes of power failures where he got seriously stressed, and had a re-breakout with ick. Nothing big, and he recovered on his own. Well, since moving him to the 210, he has broken out again, and seems to be recovering with garlic soaked food (we've named this fish 'lucky' as he has always bounced back) This brings up a question on the lifecycle of ick
If the parasite needs a host to continue to cycle and grow. Where is this recurrent ick coming from on the tang? He (and all the tank mates with him) will go for 4-5 months without any sign of ick, and then when the tang gets stressed, he breaks out again. Where is this coming from? Does the parasite lie dormant in the skin of the tang without any visible signs for months on end?
Asking this because after the tang beats the ick again, I am going to put my emperor that is currently undergoing treatment for ick in a hospital tan, back into the 210. If the ick is gone from the purple tang, I'm sure it's still in the tank for at least 6 weeks without a host, so what to do with the emperor angel? Do I keep him in the hospital tank (currently requiring 2 water changes a day due to no biofilter)?
Sorry to be so rambling, just wondering where the recurrent ick comes from on my purple tang, as there were never any new fish added to the 55 gallon, yet he would break out again when stressed.

 

[beth]

I'd suggest treating all your fish for ich. Why did you expose the 210 to ich when you had a QT??
Ich can go unnoticed if it is very mild. At is oportunistic and the minute the fish is sick, you've got a major problem on your hands. Before stocking the large tank with fish, do hypo on ALL your fish that have been exposed. Then, QT all new fish before placing them in the display. Otherwise, you are playing with fire.

 

[maury]

Let me be a little clearer on exactly what happened with the 210.
The fish had been slowly added over the past 6 months or so, with no new additions for about 7 weeks. (It has a flame, bicolor, coral beauty, green mandarin, cleaner wrasse, scooter blenny and two gold stripe maroon clowns) all those fish were (and still are) happy and healthy. The purple tang was moved from my office 55 gallon, which he outgrew. He went into the 210 on Friday afternoon of last week (10 days ago). At that time, the tang hasn't shown ANY signs of ick for 6 months. Completely spotless, and I look at him for hours each day, as he was in the tank right behind my desk at my office. There haven't been any new additions to the 55 for almost one year, and the tank has been disease free. Once the tang went into the 210, he looked fine for the first 12 hours or so. I took a trip last Saturday morning to the LFS, where I found my emperor. When I got back home with him, I noticed that the purple tang had some spots on him. I was stuck at that point with putting the emperor in and seeing how he did.
Well, after two days the purple tang had blown up with ick, but the emperor looked fine. After 4 further days, after feeding garlic, the tang started to clear, but that's when the emperor went downhill.
Now, the tang is clearing up even more, and I expect him to again look great within the week. The questions I had were, where did this ick come from? From what I've read, it just doesn't linger on on a fish for MONTHS without ANY signs of infection. Now, the emperor might have had some on him, but the purple tang had already started to break out when I got the emperor home from the LFS. Next question is once the tang has cleared, and the emperor is treated, how long until it's safe to put him back in the tank?
Don't worry Beth; I didn't put a fish that had ick on it into a clean tank with a healthy population of fish.