What Else Does Malachite Green And Formaldehyde Treat?

[Liv15]

Apart from ich.

 

[Byron]

This is not a safe treatment for many fish.  Characins, catfish (corys, loricariids), and loaches can be seriously harmed.  Salt and increased heat, or heat alone, are safer treatments.
 
Ich and the similar velvet can be stubborn and persist with no external spoits; both first attck fish in the gills (the flashing) and may never proceed to visible spots.  There are of course many other issues that can cause the same symptoms; ammonia, soft water for mollies, etc.
 
Byron.