A fountain (50) comprises a supply of water under pressure, a primary fluidic diverter (10) having an input (12) for said supply, and first and second outputs (16a, b) diverging from said input. Two control ports (20a, b) are provided with control flow to direct input flow to one or other of the two outputs that lead to the two inputs of a vortex amplifier (40). This comprises a vortex chamber (54), a radial port (50), a vortex inducing port (60) and an axial output port (58). One (16a) of the diverter outputs is connected to the vortex inducing port, the other (16b) to the radial port, so that supply to said axial output port is modulated by formation of a vortex in the chamber when flow is to the vortex inducing port. The axial port leads to a nozzle whereby a vortex spray or axial jet is produced, depending on which diverter output (16a, b) is active.