Probably a silly question or not, I don’t know. I would like to hear your opinion on this. Before I purchased my Degritter a year ago, I owned one of these Chinese ultrasonic tanks, and a CLAudio before, which I sold. Anyway, I still have my ultrasonic tank with its spinner and it was unused for a year. I thought to use it to see if it works. So, 5 minutes in the ultrasonic tank with plain distilled water, played the record, sounded great but not 100% silent, next day, same record medium program on Degritter with two drops of tergitol 15, bam, perfectly silent record! My silly question/concern. How much exposure to ultrasonics is too much? Is there anyone here who uses another ultrasonic as a prewash step before the Degritter and achieves great results?