Hmmmm, I came home tonight, no bubbles in the diffuser, but I do see some bubbles in the bottles. And little tiny ones coming from the bottom. No froth though.
I'm using 2 2Liter bottles and the Nutrafin ladder to diffuse.
I mixed it this way~
Filled up 2 1/2 cups sugar and 1/2 tsp bi-carb
Added 1.5 liters warm water
Shook the bottles to dissolve most of the sugar
Mixed 1tsp fleishmanns yeast in 1/2 cup warm water, it absorbed some water, I stirred it, then poured it into the bottle.
Then I shook the bottle to mix the yeast and water/sugar mixture.
Did I do this right??
All my connections are tight, caps, joints, the nipple for the cap is drilled in, sealed with a rubber washer and siliconed on both sides.
Edit: the bubbles I mentioned are sort of big, there's about 5 of them in a bottle, they're sitting on the top of the water.