This Research Note proposes an innovative modeling and computational scheme for investigating industrial three-phase flows with aggregation. The scheme is applied on an industrially relevant application: dissolved air flotation. Aggregate formation is modeled locally using a sophisticated subgrid model, and a concept involving massless tracer particles is invoked to transport the aggregate properties, along with the flow. The model is able to account for the formation and consumption of all entities involved and to track their respective properties, only at a moderate computational cost.