When developing B&W I have always started the timer as I begin to pour the chemicals into the film tank. So I'm about 10 seconds into the developing time by the time the tank is full of developer. I begin pouring out about 10 seconds before the time is up so the tank is empty when the time is up. (my tank takes about 10 seconds to fill and 10 seconds to dump) I'm getting ready to do C-41 and I'm concerned because the timing (and temp) is much more critical. The recommended time is around three and a half minutes. So, my question is -- should I 1) start the timer as I begin to pour developer into the tank and start dumping about 10 seconds before the end the same as I do with B&W, or 2) start the timer once the tank is full and start dumping once the full 3.5 minutes is up?