An ultrasonic cleaning apparatus with a cleaning reservoir having a plurality of chambers, which are selectably fillable with cleaning fluid. The chambers of the multi-chamber reservoir are fluidly interconnectable, the apparatus further comprising a fluid distribution pump and a controller for sequentially controlling a fluid flow between the chambers during an ultrasonic cleaning cycle. Such a multi-chamber reservoir has the advantage of reducing the total volume of fluid required to clean vessels in the reservoir, since the cleaning process can be performed in a staged or sequential procedure, and the cleaning and/or rinsing fluid reused in each chamber, allowing the apparatus to be more compact.