Methylene Blue solution is most promisingly used as a preventative against fungal and bacterial influence on freshwater fish eggs. Sometimes suggested as a treatment for ich, velvet, Cryptocaryon, Amyloodinium, other protozoa, monogenetic trematodes.
Methylene blue is far less poisonous than malachite green and formalin but also not as effective against active infections. Remove active carbon before treating aquarium.
Dose Rate: 5ml per 20 litres for fungus infections, 1ml per 15 litres for fungus on eggs.