the ozone levels dissolved in the bath or treating liquid can be adjusted before the textile is placed in the bath so as to oxidize or destroy any residue in the bath which may plate onto the textile or the ozone can be added to the bath already containing the textile micro processors can be used to monitor the system to maintain suitable concentrations dependent upon the application preferably a sample of the dyed textile is pre tested to determine the operating parameters for the temperature and the time of exposure to the ozone no pre testing is required when a washer or bath is pretreated to eliminate any residual colorants prior to treatment of the textiles residence time in the ozonated bath is dependent upon the colorant or dye and the type of fiber or textile structure generally for synthetic fibers about 3 to 5 minutes is required at temperatures at least 50 u00b0 f to 120 u00b0 f since only the plated dye or colorant is to be removed cellulosic fibers usually contain reactive dyes and temperatures about 100 u00b0 f for at least 3 minutes in a basic solution is required generally between 3 and 20 minutes depending upon the dye are required after treatment with the base and ozone the fabrics are neutralized with organic or mineral acid preferably the acid is citric acid or acetic acid the base which is used is an alkali hydroxide ammonium hydroxide or ammonium carbonate the treatment of the.