Mazy (the one with motility problems and regurgitation) was getting a whole in the morning and a half in the evening but I have increased her to a whole capsule twice a day, except on the days she gets raw egg yolk. On those days (Wednesday and Sunday) day she just gets her whole one in the morning.
The other two remain at a half capsule every other day. Once in a while I give them a whole one, just in case they need extra help this time of year, but those two never have hairball trouble, ever.