Methylene Blue

Methylene Blue

Methylene Blue

Methylene Blue (updated 7-19-2023)

What It Treats: Ammonia burn, abrasions, cuts, open wounds. Mild antiparasitic/antibacterial/antifungal properties. Probably one of the best “first response” treatments for a sick fish. Will possibly detoxify a fish that has been exposed to cyanide poisoning.

How To Treat: Comes in both liquid and powder form, or is sometimes mixed in with other medications (e.g. Nitrofuracin Green Powder). So, follow the instructions for whatever product you are using. Generally used in a 30 minute bath at double dose, but you can also dose it directly into a quarantine tank. Aerate heavily.

Dosing instructions for using 2.303% Methylene Blue solution:

1) 30 minute bath (6 ppm): 1 ml per gallon (or 1 teaspoon per 5 gallons)

2) In a quarantine tank (3 ppm): 0.5 ml per gallon (or 1 teaspoon per 10 gallons) every 48 hours for 10 days with water changes before each treatment

Pros: Highly effective “first response” treatment with minimal risk to fish.

Cons/Side Effects: Methylene Blue can destroy nitrifying bacteria (i.e. your biofilter). So, it is best used in a “simple” QT (see photo at bottom); or in a dip/bath. Methylene Blue will stain plastic, silicone, clothing, your skin, etc. (So use rubber gloves when handling it.)

More info on Methylene Blue: Aquarium Medications Part 3 | Parasite & Chemical treatments