Colombo FMC

Colombo FMC (Formalin Malachite Complex) is a classic aquarium treatment combining formalin and malachite green — two of the most historically effective antiparasitic and antifungal agents used in fish keeping. This combination is highly effective against Ichthyophthirius (white spot/ich), Oodinium (velvet), superficial fungal infections, and many ectoparasitic protozoa.

FMC is a traditional-style treatment that works rapidly and reliably at eliminating free-swimming and encysted parasite stages. Because formalin and malachite green are strong chemical agents, dosing precision is important, and fish must be monitored during the treatment period for signs of distress.

Due to its potency, FMC is best used in a hospital or quarantine tank rather than the main display aquarium, particularly where sensitive species such as loaches, catfish, or invertebrates are present.