Abstract: The fluid supply apparatus includes a plurality of supply lines (308), each line having an outlet control device (328) configurable to either allow or prevent fluid in the line flowing to a shared outlet conduit (326). A controller (332) sets the outlet control devices of one or more of the plurality of supply lines in accordance with the output of a monitoring device (336), which monitors the concentration of cleaning fluid passing through the outlet conduit, to control the fluid delivered by the delivery device and the one or more outlet control devices.