The dosage is one packet per day for days 2-5, they also recommend a 25% change after the 5th day. As for daily changes, I do them daily just before I medicate since the fresh clean water helps healing as much if not more than the medicine.
On the back of the box under indications it will hint at this. They say "No water changes, pH or temperature adjustments necessary...maintain normal filtration and air."
If you read inside they say that chemical sponges need to be removed but if your carbon is 6+ days old it can stay, though you should change it after the treatment.
The active ingredient is 10 mg minocycline activity in each packet. It says this on the back of the box under the warning.