Nice! I went with the 12 gallon because the bigger ones won't fit in my tents. How much air are you pushing through those? I'm using cheaper airstones - testing smaller ones in 2 bins, larger ones in the other. They seem to create similar turbulence and bubbles. Each 12 gallon bin holds about 6 or so gallons right up to the bottom of the net pot, and I have 15LPM pumps w/4 airstones in each currently.
For what it's worth, I did go ahead and put 1 airstone in the middle of each quadrant to spread it out. I like the way it's working. I'll post a quick video of one bubbling with the big stones, and one with the small ones next to it.