Need to remove them if you can't need a med.
This will wipe the bacteria colony out in your tank though.
o 12 Anti Crustacean & Parasite 100ml
ANTI CRUSTACEAN PARASITE No 12 : Eliminates anchor
worm, fish lice, gill maggots and leeches.
Larger higher level parasites can be introduced into the aquarium on new fish or plants. They cause life-threatening damage and should be eradicated quickly.
Crustacean parasites are very difficult to eradicate so this treatment is powerful. Therefore, take care to carefully follow all instructions and note all warnings
For use with coldwater and tropical fish in marine and freshwater systems
WARNING: This treatment negatively affects biological filtration.
Damages Plants
Do not use with UV filters
Do not use below pH 6.5
For Marines, use only in separate treatment aquarium
Use only if sure of diagnosis