I am getting 60fps with 7 fish at 800x600 with no difference at the next higher resolution.
Not bad, but the outer edges of certain fish degrade a tiny bit.
I have the URL of the drivers Feldon posted, but to be honest, I do not know where to save the file to.
The driver I should use with WindowsME would be 6.47, is that correct?
You should be getting ~60fps at 1024x768. If you are viewing the Aquarium at 800x600, you are not getting the full experience as it is really taiolered for 1024x768 or better.
Download the file to your Desktop or C:\, use WinZip to open it, and double-click the README file. E-mail me if you have further troubles.