When you make FF, you only have to use the ACV when starting your very first batch. There should be enough culture left on the sides and bottom of the container to get your next batch going. Even then, the ACV is not at all necessary, because there are enough organisms floating in ordinary room air to get a good culture going. ACV just speeds up the process, and gets some good organisms going right from the get-go. An other nice little boost would be some whey left from making yogurt. When I drain whey, I save it and dump it in the FF.