The leaven is started, it should start to smell and to be fizzing or frothing. From now on you can start to use it for all your recipes like the new leavened bread.
When you have used some, refresh it to compensate and so on...
From now on, for a feed, weigh the existing leaven and always add its weight in water, mix well, then its weight in flour and mix again (as for day 6).