Egg Methylene Blue Solution

Methylene blue has been used by aquarists and fish farmers for over a century as a safe, effective antifungal and mild antibacterial agent for egg incubation. This pre-diluted solution is ready to use without measuring or further dilution, making it safe for inexperienced breeders who might otherwise overdose with concentrated stock solution.

When added to the hatching container at the recommended rate of 1ml per litre, methylene blue stains the water a vivid blue and provides antifungal protection for 48–72 hours. Fertilised eggs resist the blue staining and develop normally; infertile eggs turn blue and can be easily identified and removed. The blue colour fades naturally as it is broken down by light and biological activity, and it does not harm newly hatched fry at the concentrations used for egg treatment.