Alfredo, I understand the zombie state (closed fins, not interested in eating or eating poorly) can be a infestation of gill flukes or external protozoans. This picture raised concerns in Paul (Tommo). This picture is Batch A and they were about eight weeks old.
This was a somewhat later picture of Batch A and after treatment.
Batch A are eight months old and look like this.
Since these thread are being watched and are considered a learning tool would you mind giving more meaning to organophosphates, MS222 etc.