Abstract: A system for fixing anodized aluminum surfaces comprises a bath (1) of nickel fluoride solution in which the items are immersed following anodization, and a tank (2), connected with the bath by way of flow and return pipelines (4, 5) and containing a negative ion exchange resin bed charged with F-fluorine ions; the solution is circulated between bath and tank by a recycle pump (3), and the resin bed will be recharged by a regeneration device (7) whenever the fluorine ions have been totally or almost totally replaced by other negative ions.