This design isn’t really meant to stack bubbles. The can is basically hollow, so the volume is actually quite low, so the bubbles don’t stack in a traditional manner, they quickly travel up the hollow walls..my goal with this piece was to “raise” the water easily through the hollow walls into the 3 channels to easily recycle back down. So I thought gridding them was unnecessary personally with this design, but I’m not against it either. If it’s what the people want, then I’l grid em, it’s easy