That article again...of course. I will state my response to that, again:
One of the articles actually states right in the abstract that allicin (extract from garlic) actually killed ich.
Here are his refrences and my responses to them:
Colorni, Angelo, Rami Avtalion, Wayne Knibb, Evelyn Berger, Barbara Colorni, & Bracha Timan. 1998. "Histopathology of sea bass (Dicentrarchus labrax) experimentally infected with Mycobacterium marinum and treated with streptomycin and garlic (Allium sativum) extract." Aquaculture 160(1998)1-17.
-This study only shows that Mycobacterium marinum is not cured by allicin. This does not apply to garlic’s anti-parasitic properties since this is a bacteria.
Ashdown, Denise & Gary Violetta. 2004. "Using Garlic as an Appetite Stimulant in Sand Tiger Sharks (Carcharias taurus)." Drum & Croaker, January 2004, Volume 35, pages 59-63.
-This study discusses garlic’s use as an appetite stimulant, which doesn’t speak to its anti-parasitic properties.
Buchmann, K., P. B. Jensen, & K. D. Kruse. 2003. "Effects of Sodium Percarbonate and Garlic Extract on Ichthyophthirius multifiliis Theronts and Tomocysts: In Vitro Experiments." North American Journal of Aquaculture, Volume 65, Number 1, pages 21-24, 2003.
“Garlic extract had no effect in low amounts (30 mg/L), but at high concentrations (117 and 570 mg/L) it killed the tomocysts within 24 h.”
-This article shows that garlic can actually kill Ich tomocysts, although more garlic is required to be effective compared to malachite green.
Colorni, Angelo & Peter Burgess. 1997. "Cryptocaryon irritans Brown 1951, the cause of 'white spot disease' in marine fish: an update." Aquarium Sciences and Conservation, volume 1, pages 217-238.
-This article’s abstract and introduction did not mention garlic.
Fairfield, Terry. 1996. "Garlic & Your Aquarium: A Preliminary report on Allium sativum and fishkeeping." Aquarium Fish Magazine, January 1996, pages 79-83.
-This is not primary scientific research, and therefore scientifically cannot be considered as proof/disproof or support/lack of support of anything.
And here are the articles I cited in my article that was published in Aquarium Fish International Magazine, about how garlic has been scientifically demonstrated to actively kill parasites.
Ankri, S., and D. Mirelman. 2001. “Antimicrobial properties of allicin from garlic.” Microbes and Infection
., and J.C. Holm. 1992. “New biocides used against sea lice compared to organo-phosphorous compounds.” Aquaculture and the Environment: Reviews of the International Conference Aquaculture Europe ‘91, Dublin, Ireland
, June 10-12, 1991. European Aquaculture Society Special Publ. pp. 393-402
Coppi, A., et al. 2006. “Antimalarial Activity of Allicin, a Biologically Active Compound from Garlic Cloves.” Antimicrobial Agents and Chemotherapy
D.L.N., 1998. “Allicin, one of the active principles of garlic, inhibits the growth of protozoan parasites.” Chemtech
Holden, C. 1997. “Fighting Parasites With Garlic.” Science
Soko, C. K
., and D.E. Barker. 2004. “Efficacy of crushed garlic and lemon juice as bio-product treatments for Ichthyophthirius multifiliis (‘ich’) infections among juvenile Nile tilapia, Oreochromis niloticus
.” Aquaculture Associaton of Canada Special Publication, 9:108-110.