I have been doing a lot of timelapse lately using Canon's remote capture software. Once a day is nice but it makes for a very rough video unless you really speed up the frame rate. My latest time lapse is of Hemianthus Callitricoides using a Macro lens, I took over 30,000 frames at 1 frame per minute. I had to stop after 3 weeks as my babysitter turned the PC off on me :-( Unfortunately my PC also wasn't powerful enough to process all those frames to compose the final video (working on new PC now but will still take a long time to complete, still resampling all the photos and removing bad frames one by one), I did however do a sample using every 100 frames, meaning approx every 1.5 hours. While the video is nice it's not as smooth as I would want it to be. Also many frames need to be omitted due to fish, snails and other critters getting in the picture. Also had a lot of undesired movement under the substrate from burrowing snails, it's really incredible just how much they move things around, only visible in time lapse. Another problem with my earlier time lapses is the amount of growth that occurs at night, just as much as during the day if not more. So my latest time lapses are using LEDs as spotlights in order to illuminate the subject during day and night.
I also ran into a problem with using the Canon A70 which seems to freeze up after approx 2000 frames, not sure why, I had to unplug it all and turn camera off and back on to continue the capture, I got into a routine of doing this once a day now. I also had to adopt a firm base for the camera so that all this turning on and off didn't move the camera and therefore ruin the timelapse.
It's a lot of fun and a lot of work too.
Here's one of my first attempts, it's one the worst but it's the only one I have available right now. It requires a DivX MPEG4 decoder to view it as it's very compressed to keep the file size down. This was a single shot taken every day, unfortunately however my son kept moving the tripod each day so I had to guess the position each time. Mush easier to do on smaller tanks on a desk where the camera can sit on a small tripod or book without anyone tripping over the tripod which needs to stay in the same position for many days or even weeks.
http://www.gpodio.com/posts/animation8.avi (1.5Mb)
(I suggest people right click on the link and save the video locally, then run it from there. My connection is a little too slow to run it directly from my web server)
Hope that helps
Giancarlo