Profile: Grease Guru offers grease trap, passive grease trap, food filter traps, and grease recovery units. We can recommend on the ideal grease recovery unit model, siting and access criteria. A grease recovery unit (GRU) is a highly effective, automated system for controlling the unwanted build-up of grease and fat at source. This is typically installed under the sink and works by skimming the grease mechanically from the tank which contains the waste water. The grease is automatically discharged into a separate container for safe disposal. GG-102 range of grease recovery units include a specification and capacity to suit all requirements The installation of these recovery units requires specialist skills.