Let me see if I have this right. You are taking a video of the Sun and you see clouds roll over the Sun. Just stop the capture.
If you are not taking a video or have stopped the video, ASICAP is no longer saving information to your hard drive. It is just displaying what the camera is seeing. It will still show a live image but will not be saving it. Once the Sun is no longer covered by clouds, then you can start a new video which will be saved to your hard drive.
JohnD