Of all the parasites it is probably the most conspicuous: the carp louse (Argulus) can be up to one centimetre large, is round and flat and belongs to the fish lice (Brachiura). They bore into the fish's flesh to feed off its blood. This puncture wound can cause infections and inflammations. When removing these animals mechanically with the help of tweezers, it is important that the fish are treated with JBL Ektol bac Pond Plus . This compound prevents an inflammation of the puncture site. My treatment tip is JBL ArguPond Plus . This product has been especially developed, among other things, for the treatment against carp lice. If not treated this disease leads to emaciation and a weakened immune system of the animals in the long term.