Air Driven Internal Protein Skimmers The Miniflotor and Midiflotor are small but powerful air-driven internal protein skimmers. Their principal operating feature is the double reaction system. Within the inner cylinder, air bubbles rise and carry large quantities of water upward. This water then falls into the outer cylinder and carries the bubbles downward to the expansion cone, where the bubbles are stopped. They then rise against the strong counter-current and carry waste products to the foam collection cup. This process ensures a long contact time and extraordinary efficiency for skimmers of these diminutive sizes. Both the Miniflotor and Midiflotor include strong holding plates that hold securely yet allow easy vertical movement of the skimmer body to regulate their foam production zone. A lime wood air stone producing very fine bubbles is included. Both models feature our patented conical riser tube within the collection cup to improve skimmate quality and production.