<a href=showthread.php?s=&postid=15161659#post15161659 target=_blank>Originally posted</a> by greenbean36191
Why try to reinvent the wheel? Ich is a very commercially important parasite and as a result there has been a lot of research on treatments. Currently, hyposalinity, copper, and tank transfer are it. There's really no sense in trying to use treatments that have already been shown to be of little or no use in controlling the parasite. It's still commercially important because there still aren't any simple treatments.
Things that have been tried unsuccessfully (not an exhaustive list):
cleaner fish and shrimp
formalin
fresh water baths (up to 18 hours)
UV sterilizers
malachite green
methylene blue
various quinine derivatives
various imidazoles (including metronidazole)
penicillin
acriflavin
pyrimethamine
potassium permanganate
sodium chlorite
nitrofurazone
para-rosaniline
aminoacridine
Things that have never been tested:
garlic derivatives
pepper derivatives
While garlic has never been directly tested for use against ich there are considerable reasons to doubt it functions as hobbyists hypothesize.
"Reef-safe" treatments that do not seem to be reef safe (definitely not exhaustive):
Rally
Stop Parasites
Some important quotes about the effectiveness of various treatment approaches (from Colorni and Burgess, 1997)-
"Chemotherapeutants added to the water are rarely absorbed through the skin of the fish in a quantity sufficient to affect the trophonts (Herwig, 1978, 1979). As tomonts, the cyst wall of C. irritans is similarly impervious to medication (the prolonged period of tomont development in C. irritans makes this parasite more difficult to eradicate than I. multifiliis). Consequently, chemotherapeutics that destroy C. irritans during its parasitic or encysted phase would probably also kill the fish (Herwig, 1978)." In other words, when the little white dots disappear from your fish, it's because of the natural lifecycle of the parasite, not the medication.
"hyposalinity does not upset the osmotic balance of the trophonts, which are not adversely affected when a prolonged (18 h) freshwater treatment is administered to the host (Colorni, 1992)."