yet another test, I solved the auto focus problem I had in my last test. I think that I have lighting, exposure, and aperture close this time. other than the fact that no salt crystals grow for a long time (until I put a small seed crystal in), I like this one.
15 sec intervals
playback around 32 FPS
auto levels + other stuff in PS batch
images took up 3GB and almost killed windows movie maker, I had to import in small increments so it wouldn't lock up. export video then import again for audio, speed-up and titles.