Jeff,
Keep the temperature at whatever the fish are used to. Marine Ich doesn't change its cycle rate much with a rise in temperature. Higher temperatures mean less dissolved gases in the water, which IS a downside.
I perform hyposalinity treatments at a salinity of 11ppt. I press the MI organisms. I haven't found any fish yet that this is a problem with, but if yours does show bad signs at this salinity, bump it up to 12ppt.
You can assist in the decrease of infecting, free-swimming Theronts by vacuuming out the tank and decorations twice a day (just after lights go on and just before lights go out).
Remember that the hyposalinity treatment is slow. Hyposalinity stresses MI and, like stress on fishes, a few get by once in a while. However, hyposalinity treatment is the easiest on the fish.
After you see the last spot on your fish, keep treating for 4 more weeks, then slowly raise the salinity to normal. Once at normal, leave the fish in quarantine another 3 weeks to verify your treatment was a success.
All fish from the infected tank have to be treated, whether you see or think they have MI or not.
Know the difference between salinity and specific gravity and use salinity for your target:
http://www.petsforum.com/personal/trevor-jones/specificgravity.html
Hold that salinity in check religiously. If your QT evaporates fairly quickly, check salinity three or four times a day and make adjustments. A single slip up and you're back to ground zero.
One of the biggest challenges is keeping the pH stable and in the right zone. Be prepared to make pH readings/tests as often as you check the salinity, AND be prepared to adjust it (pH+ additives).
Garlic is not a cure and I'd rather use additives more important than that. Soak the foods in vitamin and fat additives and add beta glucan to the food during this recovery time.
Good luck! :rollface: