It would be fine to not put the filter on circulate - the reason to put it on circulate is just so that any of the ascorbic acid won't be filtered out. If it is a problem (you don't have ciruculate on your pump), then you would just keep it on filter and add more ascorbic acid if the stain is not gone in about 3 hours. All else remains the same as posted in the sitcky. If you have any other questions feel free to ask