Ingredient risk record
Levamisole HCl
Also appears as: levamisole
An anthelmintic used against internal nematodes, and one of the few actives with an explicit invertebrate clearance that still carries carve-outs. Fritz calls Expel-P safe for invertebrates while noting some snail species may be temporarily affected and that tube worms and feather dusters may react — a level of detail most labels never reach.
Source-linked caution for
The evidence is formulation associated. It raises a warning on a product containing this ingredient but never decides the verdict.
“Safe for plants and invertebrates. Some snail species may be temporarily affected. Treatment may inhibit nitrifying bacteria.”
manufacturer page · fritzaquatics.com · checked August 16, 2026
The inference only runs one way
A product containing levamisole hcl 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 levamisole hcl
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.