Ingredient risk record
Malachite green
Also appears as: malachite green chloride
ParaGuard lists malachite green and its manufacturer advises a reduced starting dose for scaleless fish. That formulation-level instruction creates a caution signal for products listing this ingredient; it does not establish that the ingredient alone causes the sensitivity.
Source-linked caution for
The evidence is formulation associated. It raises a warning on a product containing this ingredient but never decides the verdict.
“You can use any of our medications with scaleless fish, but as they can be more sensitive, we would recommend that you begin with a 1/4 to 1/2 dose first and slowly build to the recommended dosage.”
manufacturer faq · seachem.com · checked August 16, 2026
The inference only runs one way
A product containing malachite green gets a warning. But a product without it gets nothing — no clearance, no green tick. Fritz Algae Clean Out contains no copper and is still explicitly unsafe for shrimp and snails, which is why FishyMag will not certify a product as compatible unless the manufacturer says so directly.
Treatments containing malachite green
Next steps
FishyMag reports what manufacturers say, quoted and linked. It does not diagnose illness or recommend a treatment, and it never infers that a product is safe from the absence of a warning — where no statement exists, it says so.
Formulations change. Always read the label on the bottle in your hand, and contact the manufacturer if your tank contains anything valuable or unusual.