Non Aggressive Fermentation

I have started a second "first batch". The first "real" batch I used a small Kit in a demijohn. A few days later I started a larger Kit in a fermentation bin. I noticed today though that the later one, the one in the tub, doesn't seem to bubble as much as the small demijohn. The demijohn was very aggressive bubbling a lot. The tub, in its 3rd day of primary, at 22 degrees constant, is bubbling about once every 3-5 seconds.

Should I be concerned? I do noticed there is more "space" in the tub than the demijohn but not sure if this is the reason.

I assume you have a lid on it with an airlock, since you are referring to bubbling.

All and all there is nothing to be concerned with, some brews will just ferment differently, as long as it is fermenting you should be fine.

It is not uncommon at all to have different fermentations go along at different speeds. Yeast is a living organism and isn't perfectly predictable. Also, if the "bin" is a bucket with a lid you will have some c02 seeping out the sides and the airlock or blowoff won't bubble as much.

My guess is that, because the must in the demijohn has a smaller surface area than your current primary fermentation vessel, the activity only seemed more robust.