ochremoon : ...I may test the waters with a 40KHz machine, doing one record at a time and see how it compares with the vacuum machine I currently use.@ochremoon - I believe you will find the experience rewarding and I hope you will come back and share what you discover. My 40Khz tank has about 100 hours on it and is performing well. It may not have the longevity of a U.S. or German built unit, but it is giving me excellent results. And, importantly, it is not doing any harm to the vinyl - it simply cleans.
As you move ahead, I highly encourage you to use a detergent formulation in your tank such as the formula I’ve shared. My earlier exposure to ultrasonic cleaning demonstrations using just water and alcohol with air drying were not at all compelling compared to my wet/vac manual cleaning process. With heat, a Tergitol/Triton solution in the tank, double rinsing and vacuum dry, my results with this current USC cleaning regimen are outstanding. I won’t be going back. (And, for the record, I’m using 1" spacing with 4 records at a time in this 9.5" wide 10L 40Khz tank. I’d have no hesitation doing 3 records at a time in a 6L tank with adequate width. As Terry says, it all depends on the energy distribution in the tank you're using. Do a foil test to check it out, then do follow-up tests from time to time to confirm it's still performing in the same way over time.)