Fluid container having latching interface for micro-fluid applications

A container to hold an initial or refillable volume of fluid, comprising a housing defining a fluid exit port 20 and an interior 14 to retain the volume of fluid, the interior oriented during use to deplete the volume of fluid in a direction of gravity toward a bottom surface 18 of the interior; and a mixing chamber 60 having a chamber interior 62 in fluid communication between the interior 14 of the housing and the fluid exit port, the mixing chamber 60 having fluid inlet ports F arranged to pass the volume of fluid from the interior 14 of the housing into the chamber interior 62 at multiple heights above the bottom surface 18 of the interior, wherein a topmost fluid inlet port allows direct passage of fluid from the interior 14 into the chamber along a path in the direction of gravity upon proper orientation of the housing during use.