Andy you are basically adding way to much yeast.......im surprised the nutrafin unit hasnt blown up!
One of those satchets keeps both my units going for 3-4 weeks and i change both weekly...........add 1/2 to 1/3 of a teaspoon of the yeast (not level a little bit heaped) and blend into the mix as i described to you before..........this will easily give you enough co2 to last a week and then it will slow down......but before it does change it again, im changeing mine every 8 days approx. The bread yeast you have is fine just dont add so much.
And another thing forget about the bicarb, just add the yeast and the sugar, if you are buffering the tank water itself thats fine, thats all i do, i havent used bicard in my mixes for months, it also stops the white whispy stuff that comes out the end of the co2 tube, basically you dont need it, just add the sugar to the level marked on the unit and then add the preblended yeast and top up with luke warm water and then stir the contents together, close unit, half an hour later enough co2 bubbles to do you for a week............
Sorry jimbooo i dont mean to be contradicting what you are saying, you were post as i was replying, i basically dont find any need to add the bicarb, but i agree with you dont over complicate it........
/www.homebrewit.com/aisle/350
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only joking mate - i did find without the bicarb the bubbles were rather random. one day it was blowing out a bubble every second, the next day every 3 secs, next day back to every second. i assume the bicarb stabalises the reaction. either way with or without bicarb 1/2 a tsp yeast will do the trick.
