I've also read articles by Steven Pro, who also posts on WWW, that hypo in his opinion is a good choice for treatment. Here is a quote, also from WWW:
"Hyposalinity
Hello, crew! Enjoying your information and contributions more than ever. Perhaps you can clear something up for me, what is the appropriate salinity and time period for hyposalinity treatment in a fish-only quarantine tank?
[Steven Pro] "Here is an excerpt from an article I am working on along with a few references for additional information:
Low salinity has been demonstrated to be an effective treatment against Cryptocaryon. A salt level of 14-15 ppt or 1.010-1.011 specific gravity for 7-10 days has been reported to kill the parasite. Most fish will tolerate being transferred to a low salinity tank without special acclimation procedures. The low salinity water should match the temperature and pH, though. After treatment, the fish need to be slowly acclimated back to full-strength seawater. Increasing the specific gravity 0.001 per day should be slow enough.
The drawbacks to this treatment are the same for many of the treatment options discussed above. Invertebrates and certain fish will not be able to tolerate it. Sharks and Rays are two fish groups that are not safe for this procedure. I would also not recommend this approach in the presence of liverock or livesand. The Hyposalinity will likely kill the worms, crustaceans, mollusks, and other life, causing a severe drop in overall water quality.
Kollman, Rand. 1998. “Low Salinity as Quarantine and Treatment of Marine Fish Parasites†SeaScope, Volume 15, Spring 1998.
Also, I seem to remember that Ich can be present (and actively affecting a host) while the spots do not actually appear on the fish. True?
[Steven Pro] Yes, it is not uncommon for Ich to begin in the gills, but there are signs/rapid breathing.
Thanks very much! Travis
"You are welcome. -Steven Pro"
There's just a lot of conflicting info, even on the same website and from many of the "pros" in the field, so I thought maybe Anthony shared some current insight that may be beneficial to hobbyists to make the controversy on subject a bit clearer.