Hyposalinity- weird results

[snake42490]

Hey guys, I will try to keep this as brief as possible lol. Long story short, a coral hitched along some ich which was introduced into my tank. I left the tank run for about 2 months with the ich. I was relying on immune systems to kick in and keep it under control. It worked, except it got annoying looking at my fish with spots every couple of weeks. I decided to do hypo, I am not a huge fan of using copper. I used tap water for hypo treatment, I have hard tap water and knew that it would stay stable under low salinity. I dropped the salt down to 1.0075 with a calibrated refratometer. The fish have been in there for 2 months with water changes every 3 days. So about two weeks ago I decided to start bumping up the salinity, I got it up to 1.015 and a few days later ICH is back. After two months of the fish not having a single spot on them and then it comes back once I bump it up. So here are my questions.

Does hypo actually kill the ich of does it just drive it into a state of supression where it is unable to reproduce. Basically is it sitting dormant on the bottom of the tank once it has dropped from the fish and then when I bumped up the salinity it hatched? I am 100 positive this is ich. Now the other opition i was weighing is I know some strains of ich can stay in the fish longer. Was this some ich that was just working its way though the fish still?
When the Ich came back it was only present on my scopas tang, roughly 4 specs, rest of the fish were still spotless

If this is the case where the ich drops from the fish and sits on the bottom of the tank in a state where it waits for the salt levels to raise again before it comes back what if I transfer the fish to a different tank still at 1.0075 then raise it back up. That should mean that the ich isn't transfered on the fish. Looking forward to hearing back from you guys.

As of right now I dropped the levels back down and all spots have been gone for 2 weeks now. I have now reset the time and plan on keeping fish here for another month at least.

[Dmorty217]

Hypo only prevents the ich from showing doesn't solve the problem, ich will die in a tank with no fish in anywhere for 4 to 8wks. With that said you should be dosing your food with garlic, selcon and vita chem. they all help with immunity and health. My tank definitely has ich in it but no fish show signs of it because they are eating the dosed frozen food. If I get a new fish that isn't eating right away, they immediately develop ich and if they continue to not eat they die

[Breadman03]

In the stickies for this forum, there is info about tank transfer. Basically, every 3days, you transfer the fish to a fresh tank for 4 transfers. This allows the Ich to drop to the bottom of the tank, but the fish are transferred out before the Ich can attach again.

[snake42490]

A hyposalinity treatment will kill: Pods, snails, crabs, invertebrates, corals, live rock, most marine algae, and Marine Ich. This is why it is best performed in a separate, bare bottom, hospital tank. It has been performed successfully in fish only aquariums where there is no live rock and the substrate doesn't have worms and pods in it. But the best treatment tank is a bare bottom hospital tank, set up like a quarantine tank.

I read though the sticky on hypo a couple of times, it uses the word kills off ich a bunch. I don't want the fish to just build up the immunity to the parasite. I want to rid the fish of the parasite. Giving the fish garlic food will only boost their immune systems to lower the number of parasites on their body.

I have read up on the tank transfer method and used it in the past successfully. I just didn't want to have to go through all of that work because this is my whole display tank. I have my 90 gallon QT tank set up with about 30 fish. It's not as easy when you have so many fish involved

[snake42490]

I am more curious as to why the parasite would be coming back after being in hyposalinity for so long. It says that it only needs to be in hypo for 3 weeks with time to monitor if the parasite comes back. I think I might end up trying hypo and the transfer method and just find a bucket to put the fish in.