ich hypo resistance

[zens]

I seem to have a resistant strain on one of my qt'd fish. 10 weeks in hypo at 1.008 and as soon as I start raising the salinity the specs start to reappear. It doesn't look like full blown ich but I can clearly see maybe 10 or so salt grain like raised spots. I get scared and go back to hypo conditions. The fish
has gone through two ten week hypo treatments. Is there something else that looks like ich?

[leebca]

WELCOME to REEFLAND!
Glad you're here and posting!

There have been reports from Asian aqua farms of a "hypo-resistant" strain of Marine Ich (Cryptocaryon irritans) but the likelihood it has found its way to your aquarium is very small. Not impossible, though. I'd wonder where the fish being treated came from and when/how did the parasite first show up.

There are 'white spots' on fish which include the cysts of worms and flukes. But they would not respond to a hyposalinity treatment. Do these spots 'go away' AND don't reappear when the fish is returned to hyposalinity? Is it possible that the spots aren't hiding somewhere else, out of sight, when the salinity is about to be raised?

The cysts of some parasites are white and they are often confused with Marine Ich (MI). However, a trained eye would be able to discern a difference in some cases. Usually, these spots are slightly larger than true MI spots, there are usually fewer of them, and they stay on the fish longer. If you'd like, you could post a clear, up close photo of the fish which should fill the photo frame, clearly showing one or more of these spots and I'll have a look.

It is extremely easy to contaminant a quarantine tank (QT) by re-introducing Marine Ich (MI) back into the QT during treatment. Have there have been no instances where even the smallest of drops or moist equipment (hoses, nets, tubing, etc.) coming into contact with the QT from a possible infected source of water? Was there are crusty/moist salt deposits on the edge of the tank that were allowed to fall back into the tank? During the quarantine process was there any additions or changes to the livestock in the QT?

The control during a hyposalinity treatment of the salinity is important. If the salinity was allowed to bounce around that could encourage the MI to survive. But if the salinity was controlled not only by a refractometer, but by daily measurements (or more frequent), AND water changes were done using the the correct salinity water, then control can be eliminated. How was the pH controlled during this treatment?

You didn't mention the fish you are trying to treat. However if you now switch to a copper treatment, using Cupramine (about the most gentle of all copper treatments), then that will kill MI for sure, if what you see is MI. Be sure to read this first:
Copper - Treatment, Use, Problems

If the spots represent other external parasites, a different treatment would be required. A successful copper treatment would show that they are MI parasites by killing them off in two weeks.

Ask if you have any questions. Good luck!