I'm sure the Folding is set to idle.
Anyway, the Aquarium uses 100% of the CPU even at idle. It SHOULD only use the % of CPU necessary to generate the number of frames being displayed.
On my 1400 MHz Athlon system with GeForce 2 MX400, the Aquarium shouldn't need more than 4% of the CPU to generate the ~75 frames per second needed for the video card to render.
I hope some day Will can look into this, maybe in the DirectX 7 version. It really is a problem because I don't want to run my CPU 12 degrees hotter all the time, and eventually my system locks up.
I suppose now is a bad time to mention that the Aquarium brings down my Eudora Pro 5.1 too?
I have to close Eudora to run the Aquarium.