i dont fully wean untill 12 weeks...i like them to get a GOOD start and goats tend to take a while to wean naturally.
my schedual with my girls is going along these lines
3 bottles untill 7 weeks old (8am, 3pm, 8pm)
at 6 weeks i cut them down to 2 bottles (8:30am, 7:30pm)
at 9 weeks i will be cutting them down to 1 bottle in the morning
and at 12 weeks they will be cut off from the bottle.
i dont mix milk and water because i want them to get full nutrition from the milk they are getting (ive also known goats bottle fed water who later REFUSE to drink out of a bucket)
ive known people wean as young as 6 weeks, others 8, but the general "rule" from the names i trust is to let them go a little longer on the bottle to get a much better start. especially dairy does.