Methylene Blue is effective against
superficial fungal infections of fishes. The drug may be used as an alternative
to Malachite Green for the control of fungus when it is known that the fish to
be treated are sensitive. Methylene Blue is safe for use with fish eggs and fry
for the prevention of fungal infections. As a secondary use, it is effective
against some external protozoans, such as Ich, Chilodonella and Costia.
Clinical signs of disease: increased respiration; loss of normal body color;
presence of discrete white spots; scratching on tank bottom or on objects;
lethargic behavior; white tufts or strands on body; dust like "peppered" spots
on body surface, having a yellowish cast.
For fungal infections add 1 teaspoon per 10 gallons of water.