Throughout pumping, maintain constant vacuum, prevent tank wall damage, separate heavy solids with agitation
https://wiki-cable.win/index.php/Hydro-Jetting_vs_Standard_Septic_Tank_Cleaning:_When_and_Why_to_Make_use_of_Each
During pumping, maintain constant vacuum, avoid tank wall damage, break up heavy solids with agitation, and never ever get in the tank; deadly gases need strict confined-space safety protocols.