A phase separation float assembly for use with a fuel level probe having a shaft extending into a fuel storage tank for fuel mixtures, said phase separation occurring when the concentration of water, entering the storage tank, is too great and forming a phase separation layer below the rest of the fuel, said phase separation float assembly comprising: a first float subassembly comprising a first float adapted for vertical travel along said fuel level probe shaft and a magnet, said first float having a first density; a second float subassembly comprising a second float adapted for vertical travel along said fuel level probe shaft, said second float having a second density greater than said first density; and said second float subassembly further comprising at least one stop feature which engages said first float subassembly when said first float subassembly travels vertically a predetermined distance along said fuel level probe shaft, such that further upper movement of the first float subassembly is prevented; wherein said first float density is selected such that said first float subassembly travels vertically along said shaft to engage said at least one stop feature in the presence of phase separation; wherein, the first density of the first float subassembly and the second float subassembly are selected such that both the first float subassembly and the second float subassembly are movable to rise vertically along said fuel level probe shaft in the presence of water, but only the first float subassembly is moveable to rise vertically along said fuel level probe shaft in the presence of phase separation; wherein the respective densities of the first float subassembly and the second float subassembly are normally greater than that of the liquid fuel; and wherein the phase separation float assembly further comprises a control system, the fuel level probe provides information to the control system regarding the position of said magnet along said fuel level probe shaft and wherein said control system is configured to interpret whether vertical travel of said first float subassembly along said fuel level probe shaft indicates the presence of phase separation. a first float subassembly comprising a first float adapted for vertical travel along said fuel level probe shaft and a magnet, said first float having a first density; a second float subassembly comprising a second float adapted for vertical travel along said fuel level probe shaft, said second float having a second density greater than said first density; and said second float subassembly further comprising at least one stop feature which engages said first float subassembly when said first float subassembly travels vertically a predetermined distance along said fuel level probe shaft, such that further upper movement of the first float subassembly is prevented; wherein said first float density is selected such that said first float subassembly travels vertically along said shaft to engage said at least one stop feature in the presence of phase separation; wherein, the first density of the first float subassembly and the second float subassembly are selected such that both the first float subassembly and the second float subassembly are movable to rise vertically along said fuel level probe shaft in the presence of water, but only the first float subassembly is moveable to rise vertically along said fuel level probe shaft in the presence of phase separation; wherein the respective densities of the first float subassembly and the second float subassembly are normally greater than that of the liquid fuel; and wherein the phase separation float assembly further comprises a control system, the fuel level probe provides information to the control system regarding the position of said magnet along said fuel level probe shaft and wherein said control system is configured to interpret whether vertical travel of said first float subassembly along said fuel level probe shaft indicates the presence of phase separation.