Protect your fish from parasites with medikoi wheatgerm amp garlic garlic is rich in sulphur containing compounds which give it its characteristic smell these compounds are known to have repellant propertiesr the volatile oils in garlic diffuse through the skin of the fish and into the mucus layer parasites which live in the mucus layer of the fish react to these compoundsby swimming away from them fish are most vulnerable to parasitic attack when the water starts to warm up again in the