I'll look and see if the levels are low next time I hear the noise. It doesn't happen everytime I use the machine, but I may not have run long enough during each session to cause it. The trick with the magnet is a great idea, I'll write it in my notes. All in all the machine has been great and without incident. If you know of any other chemistry that can be used instead of Ilford, let me know. I just don't know how long Ilford will keep making it.