I have my first brew going. it has been fermenting a week now. The first day it started bubbling within 6 hrs after I put the yeast in after 2 days it really slowed down just 1 bubble every 30 seconds or so. I checked it yesterday it was at 20 it needs to get down to 12. But it wasent bubbling anymore. Also when I opened it there was still yeast floating on top and it didnt seem to have any carbonation in it at all. Is it still okay do i need to add more yeast or anything?