ich

[reefer_guy]

By the way caferacermike, ich is a parasite...an invert.

Temp doesn't cause the ich to die, it just speeds up the life cycle so that it can be treated more quickly.

[reefer_guy]

http://saltaquarium.about.com/librar...blichcycle.htm

Here is a down and dirty on the cryptocaryon (saltwater ich) life cycle.

[GaryP]

So you are talking about dropping the salinity for the whole tank, not just doing a dip. OK, I see now. As long as there is nothing else in the tank that the hypo is going to kill. For example, most crustaceans. Hypo is OK in a quarantine tank, but I can't see how it is practical in a display tank, especially a reef tank. Besides, there are always going to be some dormant cysts so even hypo is not going to permanently kill Ich from a system.

Ich is fairly rare in the wild. Its mainly an opportunistic parasite that exists in fish at a non-pathological stage (disease causing). Most fish are "carriers" (especially tangs and clowns). The opportunity that it is waiting for is stress. By minimizing stress (nutritional, physical, & social) you will also minimize Ich outbreaks. Stress causes their immune natural response to be lower (just like in humans). Some stress is unavoidable though, such as shipping stress. Even there, you can do some things. For example, instead of carrying that fish home that just came out of a bag from the wholesaler, pay for it and get the LFS to hang on to it for a while and let it acclimate and make sure its feeding. Sometimes its better to go ahead and take it straight home in the wholesaler bag then let it go through the bagging and shipping process twice. Obviously, holding a fish in quarantine is one way that you can reduce stress while at the same time allowing you to use things like hypo and copper to minimize outbreaks.

[reefer_guy]

Absolutely, you cannot subject your inverts (clams, corals, shrimp, crabs) to hypo. It is only practical in a QT and only for a display of FISH ONLY. I don't agree that there will be dormant cysts. They live out their life cycle just as any other organism, although they can live in/on a fish and never explode because of the immune system of their host. As a matter of fact, if they have no host they will eventually all die off. It is new fish and water that continually brings them into your system.

I would rather quarantine the fish myself. LFS handle too many fish, too fast. They keep their systems connected and ich is rampant within their systems.

I will agree that outbreaks of ich are not usually seen in the wild, but ich is not rare there. It is just that when a fish gets sick it is usually eaten, if not by a predator then it is killed by its own kind.