I too got an SI US for Xmas. I was a little surprised at the lack of water movement -- I guess I thought it was going to be like a whirlpool or a jacuzzi effect, but the water is mostly still except for a little bubbling at the surface. Is this normal?
Well, my SI US does the same thing, and I believe that is normal. All I can be certain of, is that my ring comes out better looking (i.e. clean) than it did when I put it in.
Ultrasonic means SOUND WAVES above the pitch, frequency, that can be heard by your ears. All one sees is a small amount of wave pattern sometimes and some buzzing, maybe virbration of the water surface. Don''t overfill the ultrasonic as this cuts down its ability to create strong enough sound waves. Slight underfilling works way better than overfilling.