Time lapse photo

I'm not sure if this is the right area of expertise,video or Photo shop? but I'm looking for a photo time lapse of a pond with algae on it , erasing the algae and ending up with a clean pond, kind of a video or flash for a web site. I would like to see the algae slowly being erased, and turning clear. The length of the Flash so be short, what ever that means, again for a web site. Probably should be looped .Can this be done? Also the cost?