Material (documents, input files, routines, namelists,...) of the practical session on the marine biogeochemistry model PISCES for advanced users (given online, November 24-26, 2020). Are included: - A presentation showing the modeling choices, code architecture, and main features of PISCES. - An introduction to diagenesis and the modeling module. - A presentation of the sensitivity of PISCES to a set of parameters. - The document including the three practical sessions, a brief description of the PISCES model and the 1D configuration of NEMO-PISCES, the installation of the NEMO and CROCO configurations used in these practical sessions, and a short summary on the visualization of results with Ferret. - Sildes showing plots and comments of the main results of the practical sessions #1 "Tuning" and #3 "Sediment". - A tar file with all the necessary files for the practical sessions. Under the CDOM directory are provided the files and routines as they should be modified in session #2 "Adding a new biogeochemical tracer in PISCES" for both ocean modeling platforms NEMO and CROCO (in case you get stuck).