As for dosage, I believe the package I was using was Australian, even though I am in Canada. Therefore British measure, which I understood to be one tablet per pint. So I was dosing 500 ml poly bottles with one tablet with good results after a month at room temperature. Any smaller bottle (330-355 ml is standard bottle size) I would use half a tablet. I did only a few small bottles. You can break them with your hands, or a mallet not easy but do-able once they get older. Sometimes there are broken ones in the bag already, just find what looks like half a tab. CHEERS!