A modular mixing impeller assembly that includes one or more connection tubes, and one or more impellers configured for assembly to the one or more connection tubes. Each of the one or more impellers has a plurality of mixing blades. Each of the one or more impellers is assembled onto at least one connection tube via a friction fit such that each of the one or more impellers is configured to rotate with its attached connection tube, and wherein the assembly between impeller and connection tube creates an airtight and water-tight seal.