Partial solution replacement in recyclable persulfuric acid cleaning systems

A method of implementing cleaning solution replacement in a recyclable fluid cleaning system for semiconductor wafers includes activating electrode current for an electrolysis reactor included in the cleaning system. At least one of electrode voltage and operating time for the electrolysis reactor is monitored, until a trigger point has been reached. The trigger point includes one of the electrode voltage reaching a predetermined threshold voltage value, a process time counter reaching a predetermined counter value, and a time value that the electrode voltage has been at the threshold voltage value reaching predetermined value. The process time counter is incremented based on one or more of actual wafer processing time, wafer type, number of wafers processed, and thickness of material to be stripped. Upon reaching the trigger point, the electrode current is deactivated, and at least a portion of cleaning system fluid is drained and replaced with fresh cleaning fluid.